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From "A B (JIRA)" <j...@apache.org>
Subject [jira] Commented: (DERBY-1520) Document new SYSCS_DIAG tables
Date Fri, 23 Mar 2007 17:47:32 GMT

    [ https://issues.apache.org/jira/browse/DERBY-1520?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12483674
] 

A B commented on DERBY-1520:
----------------------------

> But if non-delimited identifiers are not that common, then it would be beneficial to
show a
> different example, one without caps and quotation marks.

Ah, I see.  That's a good idea.  But the example as it was--i.e.:

    ....
    FROM TABLE (SYSCS_DIAG.SPACE_TABLE(myspacetable)) 

was incorrect because "myspacetable" is not a valid expression in the context of this query.
 
If we assume that the intent is to have a scenario where we have delimited identifiers, then
the correct query is:

    ....
    FROM TABLE (SYSCS_DIAG.SPACE_TABLE('myspacetable')) 

i.e. the argument still has to be a string literal (and thus the quotes are required).  The
only difference is that you wouldn't
need to put the name in upper-case.  But if you use that example then you should make sure
to explicitly state that when "myspacetable" was created it was created with delimiters around
its name, ex:

  create table "myspacetable" (i int)                -- note the double-quotes as delimiters

If you want an example that does not use string literals (and thus no single quotes are required),
you have to specify some non-literal expression which is valid in the context of the query
and whose type maps to Java string.  Once such example would be:

  SELECT T2.*
    FROM
       SYS.SYSTABLES systabs,
       TABLE (SYSCS_DIAG.SPACE_TABLE(systabs.tablename)) AS T2
    WHERE systabs.tabletype = 'T'

which will return the space usage for all user tables (and indexes) in the database.  This
might be a good example to give since it sounds like something a user might actually want
to do...But I'll leave that up to you.

On a completely different note, I noticed that the latest patch is missing a space before
"tableName" in the following sentence under SYSCS_DIAG.SPACE_TABLE:

  This diagnostic table function takes two arguments, the schemaName and thetableName.

> Document new SYSCS_DIAG tables
> ------------------------------
>
>                 Key: DERBY-1520
>                 URL: https://issues.apache.org/jira/browse/DERBY-1520
>             Project: Derby
>          Issue Type: Sub-task
>          Components: Documentation
>    Affects Versions: 10.2.1.6
>            Reporter: Stan Bradbury
>         Assigned To: Laura Stewart
>         Attachments: derby1520_1.diff, derby1520_2.diff, derby1520_3.diff, derby1520_4.diff,
derby1520_5.diff, derby1520_6.diff, refderby.ditamap, rrefsyscsdiagtables.html, rrefsyscsdiagtables.html,
rrefsyscsdiagtables.html, rrefsyscsdiagtables.html
>
>
> See comments for DERBY-571 for initial documentation discussion.  The new tables (mapped
to the old Diagnostic VTIs) are:
> 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 
> The information about the tables can be found in the javadoc for the class listed above.
> That can be found at:
> http://db.apache.org/derby/javadoc/engine/
> click on the org.apache.derby.diag link in the Packages table, then select each class,
e.g. LockTable to see the info.

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