Return-Path: Delivered-To: apmail-db-derby-commits-archive@www.apache.org Received: (qmail 35817 invoked from network); 31 Mar 2005 01:29:37 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (209.237.227.199) by minotaur.apache.org with SMTP; 31 Mar 2005 01:29:37 -0000 Received: (qmail 78389 invoked by uid 500); 31 Mar 2005 01:29:37 -0000 Delivered-To: apmail-db-derby-commits-archive@db.apache.org Received: (qmail 78308 invoked by uid 500); 31 Mar 2005 01:29:36 -0000 Mailing-List: contact derby-commits-help@db.apache.org; run by ezmlm Precedence: bulk list-help: list-unsubscribe: List-Post: Reply-To: "Derby Development" Delivered-To: mailing list derby-commits@db.apache.org Received: (qmail 78287 invoked by uid 500); 31 Mar 2005 01:29:36 -0000 Delivered-To: apmail-incubator-derby-cvs@incubator.apache.org Received: (qmail 78280 invoked by uid 99); 31 Mar 2005 01:29:36 -0000 X-ASF-Spam-Status: No, hits=-9.8 required=10.0 tests=ALL_TRUSTED,NO_REAL_NAME X-Spam-Check-By: apache.org Received: from minotaur.apache.org (HELO minotaur.apache.org) (209.237.227.194) by apache.org (qpsmtpd/0.28) with SMTP; Wed, 30 Mar 2005 17:29:32 -0800 Received: (qmail 26502 invoked by uid 65534); 31 Mar 2005 00:27:30 -0000 Message-ID: <20050331002730.26500.qmail@minotaur.apache.org> Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Mailer: svnmailer-1.0.0-dev Date: Thu, 31 Mar 2005 00:27:30 -0000 Subject: svn commit: r159548 [15/17] - in incubator/derby/docs/trunk/src: adminguide/ devguide/ getstart/ tuning/ To: derby-cvs@incubator.apache.org From: jta@apache.org X-Virus-Checked: Checked X-Spam-Rating: minotaur.apache.org 1.6.2 0/1000/N Modified: incubator/derby/docs/trunk/src/tuning/rtunproper40688.dita URL: http://svn.apache.org/viewcvs/incubator/derby/docs/trunk/src/tuning/rt= unproper40688.dita?view=3Ddiff&r1=3D159547&r2=3D159548 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D --- incubator/derby/docs/trunk/src/tuning/rtunproper40688.dita (original) +++ incubator/derby/docs/trunk/src/tuning/rtunproper40688.dita Wed Mar 30 1= 6:26:36 2005 @@ -1,55 +1,55 @@ - - - - -derby.storage.pageSize - -derby.storage.pageSizePage siz= econfiguring - - - -
Function -

Defines the page size, in bytes, for on-disk database pages for tables -or indexes used during table or index creation. Page size can only be one -the following values: 4096, 8192, 16384, or 32768. Set this property prior -to issuing the CREATE TABLE or CREATE INDEX statement. This value will be -used for the lifetime of the newly created conglomerates.

-
-
Valid conglomerates -

Tables and indexes, including the indexes created to enforce constraint= s=2E

-
-
Default -

4096 bytes.

-
-
Valid values -

Page size can only be one the following values: 4096, 8192, 16384, or 3= 2768. -If you specify an invalid value, uses the default value 4096.

-
-Example --- changing the default for the system -derby.storage.pageSize=3D8192 --- changing the default for the database -CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY(=20 - 'derby.storage.pageSize', - '8192') - - -
Dynamic or static -

This property is dynamic; if you change it while is running, -the change takes effect immediately. For information about dynamic changes -to properties, see = .

-
+ + + + +derby.storage.pageSize + +derby.storage.pageSizePage siz= econfiguring + + + +
Function +

Defines the page size, in bytes, for on-disk database pages for tables +or indexes used during table or index creation. Page size can only be one +the following values: 4096, 8192, 16384, or 32768. Set this property prior +to issuing the CREATE TABLE or CREATE INDEX statement. This value will be +used for the lifetime of the newly created conglomerates.

+
+
Valid conglomerates +

Tables and indexes, including the indexes created to enforce constraint= s=2E

+
+
Default +

4096 bytes.

+
+
Valid values +

Page size can only be one the following values: 4096, 8192, 16384, or 3= 2768. +If you specify an invalid value, uses the default value 4096.

+
+Example +-- changing the default for the system +derby.storage.pageSize=3D8192 +-- changing the default for the database +CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY(=20 + 'derby.storage.pageSize', + '8192') + + +
Dynamic or static +

This property is dynamic; if you change it while is running, +the change takes effect immediately. For information about dynamic changes +to properties, see = .

+
Propchange: incubator/derby/docs/trunk/src/tuning/rtunproper40688.dita ---------------------------------------------------------------------------= --- svn:eol-style =3D native Modified: incubator/derby/docs/trunk/src/tuning/rtunproper43414.dita URL: http://svn.apache.org/viewcvs/incubator/derby/docs/trunk/src/tuning/rt= unproper43414.dita?view=3Ddiff&r1=3D159547&r2=3D159548 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D --- incubator/derby/docs/trunk/src/tuning/rtunproper43414.dita (original) +++ incubator/derby/docs/trunk/src/tuning/rtunproper43414.dita Wed Mar 30 1= 6:26:36 2005 @@ -1,39 +1,39 @@ - - - - -derby.language.logQueryPlan - -derby.language.logQueryPlanSta= tement executiondebuggingStat= ementsdebugging - - - -
Function -

When this property is set to true, writes the query plan information -into the derby.log file for all executed queries.

-

This property is useful for debugging to know what query plan was chose= n -by the optimizer.

-
-Example -derby.language.logQueryPlan=3Dtrue - -
Default -

False.

-
-
Dynamic or static -

static

-
+ + + + +derby.language.logQueryPlan + +derby.language.logQueryPlanSta= tement executiondebuggingStat= ementsdebugging + + + +
Function +

When this property is set to true, writes the query plan information +into the derby.log file for all executed queries.

+

This property is useful for debugging to know what query plan was chosen +by the optimizer.

+
+Example +derby.language.logQueryPlan=3Dtrue + +
Default +

False.

+
+
Dynamic or static +

static

+
Propchange: incubator/derby/docs/trunk/src/tuning/rtunproper43414.dita ---------------------------------------------------------------------------= --- svn:eol-style =3D native Modified: incubator/derby/docs/trunk/src/tuning/rtunproper43517.dita URL: http://svn.apache.org/viewcvs/incubator/derby/docs/trunk/src/tuning/rt= unproper43517.dita?view=3Ddiff&r1=3D159547&r2=3D159548 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D --- incubator/derby/docs/trunk/src/tuning/rtunproper43517.dita (original) +++ incubator/derby/docs/trunk/src/tuning/rtunproper43517.dita Wed Mar 30 1= 6:26:36 2005 @@ -1,43 +1,43 @@ - - - - -derby.language.logStatementText - -derby.language.logStatementTextStatement executiondebugging= Statementsdebugging - - - -
Function -

When this property is set to true, writes the text and parameter -values of all executed statements to the information log at the beginning -of execution. It also writes information about commits and rollbacks. Info= rmation -includes the time and thread number.

-

This property is useful for debugging.

-
-Example -derby.language.logStatementText=3Dtrue --- database-wide property -CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY( - 'derby.language.logStatementText', 'true') - -
Default -

False.

-
-
Dynamic or static -

static

-
+ + + + +derby.language.logStatementText + +derby.language.logStatementTextStatement executiondebugging= Statementsdebugging + + + +
Function +

When this property is set to true, writes the text and parameter +values of all executed statements to the information log at the beginning +of execution. It also writes information about commits and rollbacks. Info= rmation +includes the time and thread number.

+

This property is useful for debugging.

+
+Example +derby.language.logStatementText=3Dtrue +-- database-wide property +CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY( + 'derby.language.logStatementText', 'true') + +
Default +

False.

+
+
Dynamic or static +

static

+
Propchange: incubator/derby/docs/trunk/src/tuning/rtunproper43517.dita ---------------------------------------------------------------------------= --- svn:eol-style =3D native Modified: incubator/derby/docs/trunk/src/tuning/rtunproper46141.dita URL: http://svn.apache.org/viewcvs/incubator/derby/docs/trunk/src/tuning/rt= unproper46141.dita?view=3Ddiff&r1=3D159547&r2=3D159548 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D --- incubator/derby/docs/trunk/src/tuning/rtunproper46141.dita (original) +++ incubator/derby/docs/trunk/src/tuning/rtunproper46141.dita Wed Mar 30 1= 6:26:36 2005 @@ -1,48 +1,48 @@ - - - - -derby.locks.waitTimeout - -derby.locks.waitTimeoutDeadloc= kswait timeout property - - - -
Function -

Specifies the number of seconds after which aborts a transaction -when it is waiting for a lock. When aborts (and rolls back) the -transaction, the transaction receives an SQLException of SQLStat= e 40XL1.

-

The time specified by this property is approximate.

-

A zero value for this property means that aborts a transaction -any time it cannot immediately obtain a lock that it requests.

-

A negative value for this property is equivalent to an infinite wait ti= me; -the transaction waits forever to obtain the lock.

-

If this property is set to a value greater than or equal to zero but le= ss -than the value of = , then never= performs any deadlock checking.

-
-
Default -

60 seconds.

-
-Example -CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY( - 'derby.locks.waitTimeout', '15') -derby.locks.waitTimeout=3D60 - -
Dynamic or static -

Dynamic; the change takes effect immediately. For information about dyn= amic -changes to properties, see .

-
+ + + + +derby.locks.waitTimeout + +derby.locks.waitTimeoutDeadloc= kswait timeout property + + + +
Function +

Specifies the number of seconds after which aborts a transaction +when it is waiting for a lock. When aborts (and rolls back) the +transaction, the transaction receives an SQLException of SQLStat= e 40XL1.

+

The time specified by this property is approximate.

+

A zero value for this property means that aborts a transaction +any time it cannot immediately obtain a lock that it requests.

+

A negative value for this property is equivalent to an infinite wait ti= me; +the transaction waits forever to obtain the lock.

+

If this property is set to a value greater than or equal to zero but le= ss +than the value of = , then never= performs any deadlock checking.

+
+
Default +

60 seconds.

+
+Example +CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY( + 'derby.locks.waitTimeout', '15') +derby.locks.waitTimeout=3D60 + +
Dynamic or static +

Dynamic; the change takes effect immediately. For information about dyn= amic +changes to properties, see .

+
Propchange: incubator/derby/docs/trunk/src/tuning/rtunproper46141.dita ---------------------------------------------------------------------------= --- svn:eol-style =3D native Modified: incubator/derby/docs/trunk/src/tuning/rtunproper81359.dita URL: http://svn.apache.org/viewcvs/incubator/derby/docs/trunk/src/tuning/rt= unproper81359.dita?view=3Ddiff&r1=3D159547&r2=3D159548 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D --- incubator/derby/docs/trunk/src/tuning/rtunproper81359.dita (original) +++ incubator/derby/docs/trunk/src/tuning/rtunproper81359.dita Wed Mar 30 1= 6:26:36 2005 @@ -1,55 +1,55 @@ - - - - -derby.storage.pageCacheSize - -derby.storage.pageCacheSizePag= e cache sizeconfiguring - - - -
Function -

Defines the size, in number of pages, of the database's data page cache -(data pages kept in memory).

-

The actual amount of memory the page cache will use depends on the foll= owing: -=20 -

    -
  • the size of the cache (configured with this property, )
  • -
  • the size of the pages (configured with the property)
  • -
  • overhead (varies with JVMs)
  • -

-

When increasing the size of the page cache, you typically have to allow -more memory for the Java heap when starting the embedding application (tak= ing -into consideration, of course, the memory needs of the embedding applicati= on -as well). For example, using the default page size of 4K, a page cache siz= e -of 2000 pages will require at least 8 MB of memory (and probably more, giv= en -the overhead).

-

For a simple application (no GUI), using the Sun 1.1.7 JVM on Windows N= T -and using the -mx96m option (which allows 96 MB for the Java heap), it is -possible to have a page cache size of 10,000 pages (approximately 40 MB).<= /p> -

The minimum value is 40 pages. If you specify a lower value, uses -the default value.

-
-
Default -

1000 pages.

-
-Example -derby.storage.pageCacheSize=3D160 - -
Dynamic or static -

Static. You must reboot the system for the change to take effect.

-
+ + + + +derby.storage.pageCacheSize + +derby.storage.pageCacheSizePag= e cache sizeconfiguring + + + +
Function +

Defines the size, in number of pages, of the database's data page cache +(data pages kept in memory).

+

The actual amount of memory the page cache will use depends on the foll= owing: +=20 +

    +
  • the size of the cache (configured with this property, )
  • +
  • the size of the pages (configured with the property)
  • +
  • overhead (varies with JVMs)
  • +

+

When increasing the size of the page cache, you typically have to allow +more memory for the Java heap when starting the embedding application (tak= ing +into consideration, of course, the memory needs of the embedding applicati= on +as well). For example, using the default page size of 4K, a page cache size +of 2000 pages will require at least 8 MB of memory (and probably more, giv= en +the overhead).

+

For a simple application (no GUI), using the Sun 1.1.7 JVM on Windows NT +and using the -mx96m option (which allows 96 MB for the Java heap), it is +possible to have a page cache size of 10,000 pages (approximately 40 MB).<= /p> +

The minimum value is 40 pages. If you specify a lower value, uses +the default value.

+
+
Default +

1000 pages.

+
+Example +derby.storage.pageCacheSize=3D160 + +
Dynamic or static +

Static. You must reboot the system for the change to take effect.

+
Propchange: incubator/derby/docs/trunk/src/tuning/rtunproper81359.dita ---------------------------------------------------------------------------= --- svn:eol-style =3D native Modified: incubator/derby/docs/trunk/src/tuning/rtunproper81405.dita URL: http://svn.apache.org/viewcvs/incubator/derby/docs/trunk/src/tuning/rt= unproper81405.dita?view=3Ddiff&r1=3D159547&r2=3D159548 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D --- incubator/derby/docs/trunk/src/tuning/rtunproper81405.dita (original) +++ incubator/derby/docs/trunk/src/tuning/rtunproper81405.dita Wed Mar 30 1= 6:26:36 2005 @@ -1,55 +1,55 @@ - - - - -derby.database.forceDatabaseLock - -derby.database.forceDatabaseLock - - - -
Function -

On some platforms, if set to true, prevents from booting a -database if a db.lck file is present in the database -directory.

-

attempts to = prevent two JVMs from accessing a database at one -time (and potentially corrupting it) with the use of a file called db.l= ck in the database directory. On some operating systems, the use -of a lock file does not guarantee single access, and so only issues -a warning and might allow multiple JVM access even when the file is presen= t=2E -(For more information, see "Double-Booting System Behavior" in Chapter -1 of the .= )

-

provides the= property derby.database.forceDatabaseLock for use on platforms that= do not provide the ability for to -guarantee single JVM access. By default, this property is set to false. Wh= en -this property is set to true, if finds the db.lck file when it attempts to boot the= database, it throws an exception -and does not boot the database. =20 -This situation can occur -even when no other JVMs are accessing the database; in that case, remove t= he db.lck file by hand in order to boot the database. If -the db.lck file is removed by hand while a JVM is -still accessing a database, there is no way for to -prevent a second VM from starting up and possibly corrupting the database. -In this situation no warning message is logged to the error log. -

-
Default -

false

-
-Example -derby.database.forceDatabaseLock=3Dtrue - -
Dynamic or static -

This property is static; if you change it while is running, -the change does not take effect until you reboot.

-
+ + + + +derby.database.forceDatabaseLock + +derby.database.forceDatabaseLock + + + +
Function +

On some platforms, if set to true, prevents from booting a +database if a db.lck file is present in the database +directory.

+

attempts to = prevent two JVMs from accessing a database at one +time (and potentially corrupting it) with the use of a file called db.l= ck in the database directory. On some operating systems, the use +of a lock file does not guarantee single access, and so only issues +a warning and might allow multiple JVM access even when the file is presen= t=2E +(For more information, see "Double-Booting System Behavior" in Chapter +1 of the .= )

+

provides the= property derby.database.forceDatabaseLock for use on platforms that= do not provide the ability for to +guarantee single JVM access. By default, this property is set to false. Wh= en +this property is set to true, if finds the db.lck file when it attempts to boot the= database, it throws an exception +and does not boot the database. =20 +This situation can occur +even when no other JVMs are accessing the database; in that case, remove t= he db.lck file by hand in order to boot the database. If +the db.lck file is removed by hand while a JVM is +still accessing a database, there is no way for to +prevent a second VM from starting up and possibly corrupting the database. +In this situation no warning message is logged to the error log. +

+
Default +

false

+
+Example +derby.database.forceDatabaseLock=3Dtrue + +
Dynamic or static +

This property is static; if you change it while is running, +the change does not take effect until you reboot.

+
Propchange: incubator/derby/docs/trunk/src/tuning/rtunproper81405.dita ---------------------------------------------------------------------------= --- svn:eol-style =3D native Modified: incubator/derby/docs/trunk/src/tuning/rtunproper98166.dita URL: http://svn.apache.org/viewcvs/incubator/derby/docs/trunk/src/tuning/rt= unproper98166.dita?view=3Ddiff&r1=3D159547&r2=3D159548 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D --- incubator/derby/docs/trunk/src/tuning/rtunproper98166.dita (original) +++ incubator/derby/docs/trunk/src/tuning/rtunproper98166.dita Wed Mar 30 1= 6:26:36 2005 @@ -1,43 +1,43 @@ - - - - -derby.locks.monitor - -derby.locks.monitorLocksmonitoringDeadlocksmonit= oring - - - -
Function -

Specifies that all deadlock errors are logged to the error log. If <= xref href=3D"rtunproper26985.dita#rtunproper26985"/> is set to ignore -deadlock errors, derby.locks.monitor overrides -it.

-
-
Default -

False.

-
-Example --- system property -derby.locks.monitor=3Dtrue - -CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY( - 'derby.locks.monitor', 'true') - -
Dynamic or static -

Dynamic; the change takes effect immediately. For information about dyn= amic -changes to properties, see .

-
+ + + + +derby.locks.monitor + +derby.locks.monitorLocksmonitoringDeadlocksmonit= oring + + + +
Function +

Specifies that all deadlock errors are logged to the error log. If <= xref href=3D"rtunproper26985.dita#rtunproper26985"/> is set to ignore +deadlock errors, derby.locks.monitor overrides +it.

+
+
Default +

False.

+
+Example +-- system property +derby.locks.monitor=3Dtrue + +CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY( + 'derby.locks.monitor', 'true') + +
Dynamic or static +

Dynamic; the change takes effect immediately. For information about dyn= amic +changes to properties, see .

+
Propchange: incubator/derby/docs/trunk/src/tuning/rtunproper98166.dita ---------------------------------------------------------------------------= --- svn:eol-style =3D native Modified: incubator/derby/docs/trunk/src/tuning/rtunpropercachedn.dita URL: http://svn.apache.org/viewcvs/incubator/derby/docs/trunk/src/tuning/rt= unpropercachedn.dita?view=3Ddiff&r1=3D159547&r2=3D159548 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D --- incubator/derby/docs/trunk/src/tuning/rtunpropercachedn.dita (original) +++ incubator/derby/docs/trunk/src/tuning/rtunpropercachedn.dita Wed Mar 30= 16:26:36 2005 @@ -1,28 +1,28 @@ - - - - -Caching user DNs - - - -

This property caches user DNs (distinguished names) locally wh= en is set to <= i>LDAP and = is -set to derby.user. When you provide a user DN with -this property, = is able to avoid an LDAP search for that user's -DN before authenticating. For those users without DNs defined with this pr= operty, performs -a search using the default value of .

-
+ + + + +Caching user DNs + + + +

This property caches user DNs (distinguished names) locally wh= en is set to <= i>LDAP and = is +set to derby.user. When you provide a user DN with +this property, = is able to avoid an LDAP search for that user's +DN before authenticating. For those users without DNs defined with this pr= operty, performs +a search using the default value of .

+
Propchange: incubator/derby/docs/trunk/src/tuning/rtunpropercachedn.dita ---------------------------------------------------------------------------= --- svn:eol-style =3D native Modified: incubator/derby/docs/trunk/src/tuning/rtunsearchauthdn.dita URL: http://svn.apache.org/viewcvs/incubator/derby/docs/trunk/src/tuning/rt= unsearchauthdn.dita?view=3Ddiff&r1=3D159547&r2=3D159548 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D --- incubator/derby/docs/trunk/src/tuning/rtunsearchauthdn.dita (original) +++ incubator/derby/docs/trunk/src/tuning/rtunsearchauthdn.dita Wed Mar 30 = 16:26:36 2005 @@ -1,53 +1,53 @@ - - - - -derby.authentication.ldap.searchAuthDN - -derby.authentication.ldap.searchAuthDNLDAPconfiguring - - - -
Along with , this property indicates how should bind with the LDAP directory -server to do searches for user DN (distinguished name). This property spec= ifies -the DN; spe= cifies -the password to use for the search. =20 -

If these two properties are not specified, -an anonymous search is performed if it is supported.

=20 -

For more information -about LDAP user authentication, see "LDAP Directory Service" in Chapter -7 of the .=

-Syntax -derby.authentication.ldap.searchAuthDn=3DDN - -
Default -

If not specified, an anonymous search is performed if it is supported.<= /p> -

-Example --- system-wide property -derby.authentication.ldap.searchAuthDn=3D - cn=3Dguest,o=3DJBMSTours.com --- database-wide property -CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY( - 'derby.authentication.ldap.searchAuthDn', - 'cn=3Dguest,o=3DJBMSTours.com') - -
Dynamic or static -

Static. For system-wide properties, you must reboot for the -change to take effect. For database-wide properties, you must reboot the d= atabase -for the change to take effect.

-
+ + + + +derby.authentication.ldap.searchAuthDN + +derby.authentication.ldap.searchAuthDNLDAPconfiguring + + + +
Along with , this property indicates how should bind with the LDAP directory +server to do searches for user DN (distinguished name). This property spec= ifies +the DN; spe= cifies +the password to use for the search. =20 +

If these two properties are not specified, +an anonymous search is performed if it is supported.

=20 +

For more information +about LDAP user authentication, see "LDAP Directory Service" in Chapter +7 of the .=

+Syntax +derby.authentication.ldap.searchAuthDn=3DDN + +
Default +

If not specified, an anonymous search is performed if it is supported.<= /p> +

+Example +-- system-wide property +derby.authentication.ldap.searchAuthDn=3D + cn=3Dguest,o=3DJBMSTours.com +-- database-wide property +CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY( + 'derby.authentication.ldap.searchAuthDn', + 'cn=3Dguest,o=3DJBMSTours.com') + +
Dynamic or static +

Static. For system-wide properties, you must reboot for the +change to take effect. For database-wide properties, you must reboot the d= atabase +for the change to take effect.

+
Propchange: incubator/derby/docs/trunk/src/tuning/rtunsearchauthdn.dita ---------------------------------------------------------------------------= --- svn:eol-style =3D native Modified: incubator/derby/docs/trunk/src/tuning/rtunsearchauthpw.dita URL: http://svn.apache.org/viewcvs/incubator/derby/docs/trunk/src/tuning/rt= unsearchauthpw.dita?view=3Ddiff&r1=3D159547&r2=3D159548 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D --- incubator/derby/docs/trunk/src/tuning/rtunsearchauthpw.dita (original) +++ incubator/derby/docs/trunk/src/tuning/rtunsearchauthpw.dita Wed Mar 30 = 16:26:36 2005 @@ -1,46 +1,46 @@ - - - - - -derby.authentication.ldap.searchAuthPW - -derby.authentication.ldap.searchAuthPWLDAPconfiguring - - - -
Along with , indicates -how should bind= with the directory server to do searches in order to -retrieve a fully qualified user DN. This property specifies the password; = specifies the = DN to use -for the search.

For more information about LDAP user authentication, -see "LDAP Directory Service" in Chapter 7 of the .

-
Default

If not specified, an anonymous search i= s -performed if it is supported.

-Example -- system-wide property<= /ph> -derby.authentication.ldap.searchAuthPW=3DguestPassword --- database-wide property -CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY( - 'derby.authentication.ldap.searchAuthPW', - 'guestPassword') -
Dynamic or static

Static. For system-wide prope= rties, -you must reboot = for the change to take effect. For database-wide properties, -you must reboot the database for the change to take effect.

-
-
- + + + + + +derby.authentication.ldap.searchAuthPW + +derby.authentication.ldap.searchAuthPWLDAPconfiguring + + + +
Along with , indicates +how should bind= with the directory server to do searches in order to +retrieve a fully qualified user DN. This property specifies the password; = specifies the = DN to use +for the search.

For more information about LDAP user authentication, +see "LDAP Directory Service" in Chapter 7 of the .

+
Default

If not specified, an anonymous search is +performed if it is supported.

+Example -- system-wide property<= /ph> +derby.authentication.ldap.searchAuthPW=3DguestPassword +-- database-wide property +CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY( + 'derby.authentication.ldap.searchAuthPW', + 'guestPassword') +
Dynamic or static

Static. For system-wide prope= rties, +you must reboot = for the change to take effect. For database-wide properties, +you must reboot the database for the change to take effect.

+
+
+ Propchange: incubator/derby/docs/trunk/src/tuning/rtunsearchauthpw.dita ---------------------------------------------------------------------------= --- svn:eol-style =3D native Modified: incubator/derby/docs/trunk/src/tuning/rtunstorminrecsize.dita URL: http://svn.apache.org/viewcvs/incubator/derby/docs/trunk/src/tuning/rt= unstorminrecsize.dita?view=3Ddiff&r1=3D159547&r2=3D159548 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D --- incubator/derby/docs/trunk/src/tuning/rtunstorminrecsize.dita (original) +++ incubator/derby/docs/trunk/src/tuning/rtunstorminrecsize.dita Wed Mar 3= 0 16:26:36 2005 @@ -1,63 +1,63 @@ - - - - -derby.storage.minimumRecordSize - -derby.storage.minimumRecordSize - - - -
Indicates the minimum user row size in bytes for on-disk database -pages for tables when you are creating a table. This property ensures that -there is enough room for a row to grow on a page when updated without havi= ng -to overflow. This is generally most useful for VARCHAR and VARCHAR FOR BIT -DATA data types and for tables that are updated a lot, in which the rows s= tart -small and grow due to updates. Reserving the space at the time of insertio= n -minimizes row overflow due to updates, but it can result in wasted space. -Set the property prior to issuing the CREATE TABLE statement.=20 -

See also .<= /p>

-
Valid conglomerates -

Tables only.

-
-
Default -

12 bytes.

-
-
Minimum value -

12 bytes.

-
-
Maximum value -

* (1 -- /100) " -100.

-

If you set this property to a value outside the legal range, uses -the default value.

-
-Example --- changing the default for the system -derby.storage.minimumRecordSize=3D128 --- changing the default for the database -CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY(=20 - 'derby.storage.minimumRecordSize', - '128') - - -
Dynamic or static -

This property is dynamic; if you change it while is running, -the change takes effect immediately. For information about dynamic changes -to properties, see = .

-
+ + + + +derby.storage.minimumRecordSize + +derby.storage.minimumRecordSize + + + +
Indicates the minimum user row size in bytes for on-disk database +pages for tables when you are creating a table. This property ensures that +there is enough room for a row to grow on a page when updated without havi= ng +to overflow. This is generally most useful for VARCHAR and VARCHAR FOR BIT +DATA data types and for tables that are updated a lot, in which the rows s= tart +small and grow due to updates. Reserving the space at the time of insertion +minimizes row overflow due to updates, but it can result in wasted space. +Set the property prior to issuing the CREATE TABLE statement.=20 +

See also .<= /p>

+
Valid conglomerates +

Tables only.

+
+
Default +

12 bytes.

+
+
Minimum value +

12 bytes.

+
+
Maximum value +

* (1 +- /100) " +100.

+

If you set this property to a value outside the legal range, uses +the default value.

+
+Example +-- changing the default for the system +derby.storage.minimumRecordSize=3D128 +-- changing the default for the database +CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY(=20 + 'derby.storage.minimumRecordSize', + '128') + + +
Dynamic or static +

This property is dynamic; if you change it while is running, +the change takes effect immediately. For information about dynamic changes +to properties, see = .

+
Propchange: incubator/derby/docs/trunk/src/tuning/rtunstorminrecsize.dita ---------------------------------------------------------------------------= --- svn:eol-style =3D native Modified: incubator/derby/docs/trunk/src/tuning/rtuntrademderby.dita URL: http://svn.apache.org/viewcvs/incubator/derby/docs/trunk/src/tuning/rt= untrademderby.dita?view=3Ddiff&r1=3D159547&r2=3D159548 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D --- incubator/derby/docs/trunk/src/tuning/rtuntrademderby.dita (original) +++ incubator/derby/docs/trunk/src/tuning/rtuntrademderby.dita Wed Mar 30 1= 6:26:36 2005 @@ -1,54 +1,54 @@ - - - - - -Trademarks - -

The following terms are trademarks of International Business Machines C= orporation -in the United States, other countries, or both, and have been used in at l= east -one of the documents in the DB2 UDB documentation library.

- - - - -Cloudscape -DB2 -DB2 Universal Database - - DRDA -IBM -WebSphere - - - -
-

The following terms are trademarks or registered trademarks of other co= mpanies -and have been used in at least one of the documents in the documentation -library:

-

Microsoft, Windows, Windows NT, and the Windows logo are trademarks of -Microsoft Corporation in the United States, other countries, or both.

-

Java and all Java-based trademarks are trademarks of Sun Microsystems, -Inc. in the United States, other countries, or both.

-

UNIX is a registered trademark of The Open Group in the United States a= nd -other countries.

-

Other company, product, or service names may be trademarks or service m= arks -of others.

- -
- + + + + + +Trademarks + +

The following terms are trademarks of International Business Machines C= orporation +in the United States, other countries, or both, and have been used in at l= east +one of the documents in the DB2 UDB documentation library.

+ + + + +Cloudscape +DB2 +DB2 Universal Database + + DRDA +IBM +WebSphere + + + +
+

The following terms are trademarks or registered trademarks of other co= mpanies +and have been used in at least one of the documents in the documentation +library:

+

Microsoft, Windows, Windows NT, and the Windows logo are trademarks of +Microsoft Corporation in the United States, other countries, or both.

+

Java and all Java-based trademarks are trademarks of Sun Microsystems, +Inc. in the United States, other countries, or both.

+

UNIX is a registered trademark of The Open Group in the United States a= nd +other countries.

+

Other company, product, or service names may be trademarks or service m= arks +of others.

+ +
+ Propchange: incubator/derby/docs/trunk/src/tuning/rtuntrademderby.dita ---------------------------------------------------------------------------= --- svn:eol-style =3D native Modified: incubator/derby/docs/trunk/src/tuning/rtuntransform139.dita URL: http://svn.apache.org/viewcvs/incubator/derby/docs/trunk/src/tuning/rt= untransform139.dita?view=3Ddiff&r1=3D159547&r2=3D159548 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D --- incubator/derby/docs/trunk/src/tuning/rtuntransform139.dita (original) +++ incubator/derby/docs/trunk/src/tuning/rtuntransform139.dita Wed Mar 30 = 16:26:36 2005 @@ -1,34 +1,34 @@ - - - - -BETWEEN transformations - - -BETWEEN transformations -Internal transformation of statementsBETWEEN predica= tes - - - - -

A BETWEEN predicate is transformed into equivalent predicates = that use -the >=3D and <=3D operators, which are optimizable. For example: =20 -flight_date BETWEEN DATE('2004-04-01') and DATE('2004-04-10'= )

-

is transformed into =20 -flight_date >=3D DATE('2004-04-01') -AND flight_date >=3D '2004-04-10'

-
+ + + + +BETWEEN transformations + + +BETWEEN transformations +Internal transformation of statementsBETWEEN predica= tes + + + + +

A BETWEEN predicate is transformed into equivalent predicates = that use +the >=3D and <=3D operators, which are optimizable. For example: =20 +flight_date BETWEEN DATE('2004-04-01') and DATE('2004-04-10'= )

+

is transformed into =20 +flight_date >=3D DATE('2004-04-01') +AND flight_date >=3D '2004-04-10'

+
Propchange: incubator/derby/docs/trunk/src/tuning/rtuntransform139.dita ---------------------------------------------------------------------------= --- svn:eol-style =3D native Modified: incubator/derby/docs/trunk/src/tuning/rtuntransform208.dita URL: http://svn.apache.org/viewcvs/incubator/derby/docs/trunk/src/tuning/rt= untransform208.dita?view=3Ddiff&r1=3D159547&r2=3D159548 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D --- incubator/derby/docs/trunk/src/tuning/rtuntransform208.dita (original) +++ incubator/derby/docs/trunk/src/tuning/rtuntransform208.dita Wed Mar 30 = 16:26:36 2005 @@ -1,33 +1,33 @@ - - - - -LIKE transformations - - -LIKE transformations -Internal transformation of statementsLIKE predicates= - - - -
-
    -
  • -
  • -
  • -
-
+ + + + +LIKE transformations + + +LIKE transformations +Internal transformation of statementsLIKE predicates= + + + +
+
    +
  • +
  • +
  • +
+
Propchange: incubator/derby/docs/trunk/src/tuning/rtuntransform208.dita ---------------------------------------------------------------------------= --- svn:eol-style =3D native Modified: incubator/derby/docs/trunk/src/tuning/rtuntransform345.dita URL: http://svn.apache.org/viewcvs/incubator/derby/docs/trunk/src/tuning/rt= untransform345.dita?view=3Ddiff&r1=3D159547&r2=3D159548 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D --- incubator/derby/docs/trunk/src/tuning/rtuntransform345.dita (original) +++ incubator/derby/docs/trunk/src/tuning/rtuntransform345.dita Wed Mar 30 = 16:26:36 2005 @@ -1,41 +1,41 @@ - - - - -Character string beginning with constant - - - -

A LIKE predicate in which a column is compared to a character = string that begins with a character constant (not a wildcard) is tra= nsformed -into three predicates: one predicate that uses the LIKE operator, one that -uses the >=3D operator, and one that uses the < operator. For exampl= e: - =20 -country LIKE 'Ch%i%'

-

becomes =20 -country LIKE 'Ch%i%' -AND country >=3D 'Ch' -AND country < 'Ci'

-

The first (LIKE) predicate is not optimizable, but the new pre= dicates added -by the transformation are.

-

When the character string begins with one more character const= ants and -ends with a single "%", the first LIKE clause is eliminated. For example: -=20 -country LIKE 'Ch%'

-

becomes =20 -country >=3D 'Ch' -AND country < 'Ci'

-
+ + + + +Character string beginning with constant + + + +

A LIKE predicate in which a column is compared to a character = string that begins with a character constant (not a wildcard) is tra= nsformed +into three predicates: one predicate that uses the LIKE operator, one that +uses the >=3D operator, and one that uses the < operator. For exampl= e: + =20 +country LIKE 'Ch%i%'

+

becomes =20 +country LIKE 'Ch%i%' +AND country >=3D 'Ch' +AND country < 'Ci'

+

The first (LIKE) predicate is not optimizable, but the new pre= dicates added +by the transformation are.

+

When the character string begins with one more character const= ants and +ends with a single "%", the first LIKE clause is eliminated. For example: +=20 +country LIKE 'Ch%'

+

becomes =20 +country >=3D 'Ch' +AND country < 'Ci'

+
Propchange: incubator/derby/docs/trunk/src/tuning/rtuntransform345.dita ---------------------------------------------------------------------------= --- svn:eol-style =3D native Modified: incubator/derby/docs/trunk/src/tuning/rtuntransform443.dita URL: http://svn.apache.org/viewcvs/incubator/derby/docs/trunk/src/tuning/rt= untransform443.dita?view=3Ddiff&r1=3D159547&r2=3D159548 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D --- incubator/derby/docs/trunk/src/tuning/rtuntransform443.dita (original) +++ incubator/derby/docs/trunk/src/tuning/rtuntransform443.dita Wed Mar 30 = 16:26:36 2005 @@ -1,34 +1,34 @@ - - - - -Character string without wildcards - - - -

A LIKE predicate is transformed into a predicate that uses the= =3D operator -(and a NOT LIKE predicate is transformed into one that uses <>) when -the character string does not contain any wildcards. For example: =20 -country LIKE 'Chile'

-

becomes =20 -country =3D 'Chile'

-

and =20 -country NOT LIKE 'Chile'

-

becomes =20 -country <> 'Chile'

-

Predicates that use the =3D operator are optimizable.= Predicates that use the <> operator are sargable.

- + + + + +Character string without wildcards + + + +

A LIKE predicate is transformed into a predicate that uses the= =3D operator +(and a NOT LIKE predicate is transformed into one that uses <>) when +the character string does not contain any wildcards. For example: =20 +country LIKE 'Chile'

+

becomes =20 +country =3D 'Chile'

+

and =20 +country NOT LIKE 'Chile'

+

becomes =20 +country <> 'Chile'

+

Predicates that use the =3D operator are optimizable.= Predicates that use the <> operator are sargable.

+ Propchange: incubator/derby/docs/trunk/src/tuning/rtuntransform443.dita ---------------------------------------------------------------------------= --- svn:eol-style =3D native Modified: incubator/derby/docs/trunk/src/tuning/rtuntransform472.dita URL: http://svn.apache.org/viewcvs/incubator/derby/docs/trunk/src/tuning/rt= untransform472.dita?view=3Ddiff&r1=3D159547&r2=3D159548 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D --- incubator/derby/docs/trunk/src/tuning/rtuntransform472.dita (original) +++ incubator/derby/docs/trunk/src/tuning/rtuntransform472.dita Wed Mar 30 = 16:26:36 2005 @@ -1,41 +1,41 @@ - - - - -Unknown parameter - - - -

'The situation is similar to those described above when a colu= mn is compared -using the LIKE operator to a parameter whose value is unknown in advance (= dynamic -parameter, join column, etc.).

-

In this situation, the LIKE predicate is likewise transformed = into three -predicates: one LIKE predicate, one predicate using the >=3D operator, = and -one predicate using the < operator. For example: =20 -country LIKE ?

-

is transformed into =20 -country LIKE ? -AND country >=3D InternallyGeneratedParameter -AND country < InternallyGeneratedParameter

-

where the InternallyGeneratedParameters are calculated -at the beginning of execution based on the value of the parameter. =20 -This transformation can lead to a bad plan if the user passes in -a string that begins with a wildcard or a nonselective string as the param= eter. -Users can work around this possibility by writing the query like this (whi= ch -is not optimizable): =20 -(country || '') LIKE ?

-
+ + + + +Unknown parameter + + + +

'The situation is similar to those described above when a colu= mn is compared +using the LIKE operator to a parameter whose value is unknown in advance (= dynamic +parameter, join column, etc.).

+

In this situation, the LIKE predicate is likewise transformed = into three +predicates: one LIKE predicate, one predicate using the >=3D operator, = and +one predicate using the < operator. For example: =20 +country LIKE ?

+

is transformed into =20 +country LIKE ? +AND country >=3D InternallyGeneratedParameter +AND country < InternallyGeneratedParameter

+

where the InternallyGeneratedParameters are calculated +at the beginning of execution based on the value of the parameter. =20 +This transformation can lead to a bad plan if the user passes in +a string that begins with a wildcard or a nonselective string as the param= eter. +Users can work around this possibility by writing the query like this (whi= ch +is not optimizable): =20 +(country || '') LIKE ?

+
Propchange: incubator/derby/docs/trunk/src/tuning/rtuntransform472.dita ---------------------------------------------------------------------------= --- svn:eol-style =3D native