[#DERBY-822] Client driver: Pre-fetch data on executeQuery()

Derby

Client driver: Pre-fetch data on executeQuery()

Created: 18/Jan/06 07:52 PM Updated: 30/Jun/09 04:12 PM

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Component/s:

Network Server

Affects Version/s:

10.2.1.6

Fix Version/s:

10.2.1.6

Time Tracking:

Issue & Sub-Tasks

Issue Only

Not Specified

File Attachments:

File Name	Date Attached	Attached By	Size
DERBY-822-v1.diff	2006-02-17 10:58 PM	Knut Anders Hatlen	813 kB
DERBY-822-v1.stat	2006-02-17 10:58 PM	Knut Anders Hatlen	1 kB
DERBY-822-v2.diff	2006-04-05 09:56 PM	Knut Anders Hatlen	12 kB
DERBY-822-v2.stat	2006-04-05 09:56 PM	Knut Anders Hatlen	0.5 kB
DERBY-822-v3.diff	2006-04-18 04:51 AM	Knut Anders Hatlen	10 kB
DERBY-822-v3.stat	2006-04-18 04:51 AM	Knut Anders Hatlen	0.5 kB

Issue & fix info:	Release Note Needed
Bug behavior facts:	Performance
Resolution Date:	18/Apr/06 01:55 PM

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Description

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Currently, the client driver does not pre-fetch data when
executeQuery() is called, but it does on the first call to
ResultSet.next(). Pre-fetching data on executeQuery() would reduce
network traffic and improve performance.

The DRDA protocol supports this. From the description of OPNQRY (open
query):

  The qryrowset parameter specifies whether a rowset of rows is to be
  returned with the command. This is only honored for non-dynamic
  scrollable cursors (QRYATTSNS not equal to QRYSNSDYN) and for
  non-scrollable cursors conforming to the limited block query
  protocol. The target server fetches no more than the requested
  number of rows. It may fetch fewer rows if it is restricted by extra
  query block limits, or if a fetch operation results in a negative
  SQLSTATE or an SQLSTATE of 02000.

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Work Log

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Repository	Revision	Date	User	Message
ASF	#387214	Mon Mar 20 14:20:56 UTC 2006	kahatlen	~~DERBY-1014~~: Make tests less sensitive to pre-fetching Attached a patch (~~DERBY-1014~~-v1.diff) which modifies tests in preparation for ~~DERBY-822~~. There are two types of changes: 1) Invoke ResultSet.next() to expose error even when the driver isn't pre-fetching data. 2) Filter out some of the run-time statistics before comparing with the canon. lang/wisconsin.java: * Added patterns to the sed file. Cursor names and some of the run-time statistics are filtered out. * Canons for DerbyNet and DerbyNetClient were deleted since they are no longer needed. Each of these files is 1.5M, so the diff is huge. lang/scrollCursors1.sql: * Added patterns to the sed file. Number of rows seen and number of reads from hash table will be filtered out. jdbcapi/parameterMetaDataJdbc30.java: * Added a call to ResultSet.next() to provoke an error in a test case for ~~DERBY-44~~ regardless of framework/pre-fetching. jdbcapi/resultset.java: * Don't print column headers until one row is successfully retrieved (achieved by calling ResultSet.next() earlier). jdbcapi/setTransactionIsolation.java: * Added a call to ResultSet.next() to provoke a timeout regardless of framework/pre-fetching. * Added patterns to the sed file. Filtered out number of pages visited, number of rows qualified/visited etc.
				Files Changed
				MODIFY /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/master/DerbyNetClient/setTransactionIsolation.out DEL /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/master/DerbyNetClient/wisconsin.out ADD /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/lang/scrollCursors1_sed.properties MODIFY /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/jdbcapi/setTransactionIsolation_sed.properties MODIFY /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/master/DerbyNet/resultset.out MODIFY /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/jdbcapi/setTransactionIsolation.java MODIFY /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/jdbcapi/parameterMetaDataJdbc30.java MODIFY /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/master/DerbyNetClient/scrollCursors1.out MODIFY /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/master/setTransactionIsolation.out MODIFY /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/master/DerbyNetClient/resultset.out MODIFY /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/master/DerbyNet/setTransactionIsolation.out MODIFY /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/lang/copyfiles.ant MODIFY /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/jdbcapi/resultset.java MODIFY /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/master/wisconsin.out MODIFY /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/lang/wisconsin_sed.properties DEL /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/master/DerbyNet/wisconsin.out MODIFY /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/master/DerbyNet/scrollCursors1.out MODIFY /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/master/scrollCursors1.out

Repository	Revision	Date	User	Message
ASF	#394859	Tue Apr 18 06:41:04 UTC 2006	kahatlen	~~DERBY-822~~: Client driver: Pre-fetch data on executeQuery() This patch makes the network server include query data when it replies to an OPNQRY command. (Query data is only included when there are no LOB columns and the protocol is limited block protocol.)
				Files Changed
				MODIFY /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/master/DerbyNet/supersimple.out MODIFY /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/master/DerbyNetClient/forupdate.out MODIFY /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/derbynet/values1.inc MODIFY /db/derby/code/trunk/java/drda/org/apache/derby/impl/drda/DRDAStatement.java MODIFY /db/derby/code/trunk/java/drda/org/apache/derby/impl/drda/DRDAConnThread.java MODIFY /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/master/DerbyNetClient/supersimple.out MODIFY /db/derby/code/trunk/java/drda/org/apache/derby/impl/drda/DRDAResultSet.java