db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Westerfeld, Kurt" <kwesterf...@managedobjects.com>
Subject RE: [jira] Closed: (DERBY-571) Virtual Table Mapping for no argument Diagnostic tables
Date Mon, 21 Nov 2005 16:50:52 GMT
Was the syntax CREATE VIRTUAL TABLE implemented with these changes, or
are they hard-wired for internal tables only now?

 

________________________________

From: Myrna van Lunteren [mailto:m.v.lunteren@gmail.com] 
Sent: Saturday, November 19, 2005 2:26 AM
To: derby-dev@db.apache.org
Subject: Re: [jira] Closed: (DERBY-571) Virtual Table Mapping for no
argument Diagnostic tables

 

Hi Dan,

 

To get this documented in the manuals, do we need an extra JIRA, or are
you already taking care of this?

 

Myrna

 

On 11/18/05, Daniel John Debrunner (JIRA) <derby-dev@db.apache.org>
wrote: 

    [ http://issues.apache.org/jira/browse/DERBY-571?page=all ]

Daniel John Debrunner closed DERBY-571:
---------------------------------------


> Virtual Table Mapping for no argument Diagnostic tables
> ------------------------------------------------------- 
>
>          Key: DERBY-571
>          URL: http://issues.apache.org/jira/browse/DERBY-571
>      Project: Derby
>         Type: Improvement 
>   Components: SQL
>     Reporter: Daniel John Debrunner
>     Assignee: Daniel John Debrunner
>     Priority: Minor
>      Fix For: 10.2.0.0

>
> Currently four no-argument diagnostic tables exist that provide
information about the running state of Derby, or its error messages. 
> These tables are invoked using an awkward, non-standard syntax. As an
example:
> SELECT * FROM NEW org.apache.derby.diag.LockTable() as LOCK_TABLE
> The improvement will provide an internal mapping from a regular table
name in the SYSCS_DIAG schema 
> to the runtime virtual table code. Thus the above example would be
replaced by:
> SELECT * FROM SYSCS_DIAG.LOCK_TABLE
> These diagnostic table expressions are regular table expressions (as
is the NEW VTI construct) and 
> can be used wherever a normal table can.
> Any DDL, INSERT/UPDATE/DELETE, compression procedure etc. that
references a diagnostic table
> will result in an exception.
> The old style syntax will remain in place for 10.2, but become
deprecated.
> The tables to be implemented in this change are:
> SYSCS_DIAG.LOCK_TABLE   replaces org.apache.derby.diag.LockTable
> SYSCS_DIAG.STATEMENT_CACHE    replaces
org.apache.derby.diag.StatementCache 
> SYSCS_DIAG.TRANSACTION_TABLE    replaces
org.apache.derby.diag.TransactionTable
> SYSCS_DIAG.ERROR_MESSAGES    replaces
org.apache.derby.diag.ErrorMessages
> Adding such a table will be table driven, thus easy for others to
provide additional diagnostics. 
> Information about these diagnostic tables will not appear in the
system catalogs or JDBC DatabaseMetaData.
> The ResultSetMetaData for the any query involving a diagnostic table
will be valid.
> This is a first step in a progression towards supporing a fully
application/user defined virtual table. 
> These steps are not part of this jira issue, but added for information
purposes.
> - second step - supporting diagnostic tables with parameters, e.g.
>   SELECT * FROM SYSCS_DIAG.SPACE_TABLE('sales', 'orders'); 
> - third step - providing a create virtual table statement (most
databases support
>    some form of virtual table, or wrappers). The DDL would be
non-standard but the
>    data access would be standard. [need to check table functions in
part 13 of SQL standard] 
>    E.g. syntax yet to be defined, but to give the general idea
>       CREATE VIRTUAL TABLE (TICKER VARCHAR(10), START TIMESTAMP, END
TIMESTAMP)
>            LANGUAGE JAVA
>            PARAMETER STYLE JAVA 
>            EXTERNAL NAME 'com.acme.stocks.historyFromYahooFinance';

--
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators:
  http://issues.apache.org/jira/secure/Administrators.jspa
-
For more information on JIRA, see:
   http://www.atlassian.com/software/jira
<http://www.atlassian.com/software/jira> 

 


Mime
View raw message