#DateForumTypeThreadPost
19105 Oct 2015 @ 09:06 PDTGeneralReplyTuning the SQL queryTo better understand the question we would need to know the SQL conditions relating the tables. Are these conditions selective or is it expected that the entire 5 billion rows would be included in ...
19028 Sep 2015 @ 01:13 PDTDatabaseReplySHOW Statistics - Meaning of AvgRowsPerBlock Optimizer team has opened a bug report to fix the calculation. Good news is that Dieter's solution to ignore it is fine since that value is not used in query optimization from that source.
18924 Sep 2015 @ 09:20 PDTToolsReplyNumber of Utility Load SlotsStream operator does not require a load slot.
18822 Sep 2015 @ 06:33 PDTDatabaseReplyNo Primary Index - skewingA table that small will always be skewed. We round robin at the block level not the row level. A small number of amps will receive blocks and the rest will receive no data. Any table with less data...
18717 Sep 2015 @ 02:48 PDTDatabaseReplyCollect Stats - How Performance gets improved?If it is frequently accessed via a condition (as opposed to just appearing in the select result list) then it is important to collect stats. The optimizer will assume any column without stats ...
18617 Sep 2015 @ 02:35 PDTDatabaseReplyConcurrent insert and read on same tableYou can use partitions to accomplish the loading part but only if your system is running Teradata 15.10.   All users may read as much as they want as long as they utilize access locks - spec...
18516 Sep 2015 @ 01:05 PDTDatabaseReplyConcurrent insert and read on same tablePlease describe what you mean by an "instance"? And what is the goal of having 50 instances rather than feeding all the data to a single load utility execution?   On Teradata 15.10...
18416 Sep 2015 @ 03:44 PDTDatabaseReplyAll amp duplication issuePlease provide the explain. 
18314 Sep 2015 @ 02:52 PDTDatabaseReplyPartitioning IssueI haven't seen the explain using the =1 view and tables with a real amount of data rather than test tables with just a couple rows each.
18211 Sep 2015 @ 05:50 PDTDatabaseReplyPartitioning IssueMaking progress... At the top it says that it is not doing incremental planning because it does not meet cost thresholds. That means that the brute force plan is too cheap to execute to spend time ...
18110 Sep 2015 @ 12:08 PDTDatabaseReplyPartitioning IssueYour note above says TMP_RUNDATE is "not" a single row table, but then your most recent note says the view returns exactly one row. Can you explain this part further?   Not only do...
18009 Sep 2015 @ 11:02 PDTDatabaseReplyPartitioning IssueThank you for all the information, very helpful. I see that you have the appropriate check constraints in the underlying table. Still looking for the view definition of TMP_RUNDATE and the full ex...
17909 Sep 2015 @ 08:00 PDTDatabaseReplyPartitioning IssuePlease provide: - Teradata release you are running - view definition for V_TMP_RUNDATE and table def for the table it refers to - full explain of your query including the first lines of the expl...
17803 Sep 2015 @ 12:37 PDTDatabaseReplyTable Size/NoPI vs PII am too used to talking about columnar these days... My point 1 above is correct for columnar but not for a row form NoPI table. The row form NoPI table still has a rowid. Sorry if I confused anyo...
17702 Sep 2015 @ 08:18 PDTDatabaseReplyTable Size/NoPI vs PI1. The PI table has a PI, therefore it has an 8 byte rowid added to each row. 8 * 3B is 24GB of just rowids. And as you said it is a unique PI these bytes will not compress a lot.    2....
17628 Aug 2015 @ 12:48 PDTGeneralReply1 MB data block size in 14.10It will NOT increase spool size. We always qualify from the source table before writing to spool so the block size of the table does not affect the size of the spool. It is correct that if a query ...
17510 Aug 2015 @ 06:38 PDTDatabaseReplycreating a view on a SQL query starting with "WITH" clauseCommon Table Expressions (WITH clause) is not allowed in views or derived tables. This functionality is on the to-do list but has not made it to the top yet.
17407 Aug 2015 @ 11:05 PDTDatabaseReplyError 3782 Improper column reference in the search condiditon of a joined tableAnd in the ON condition: fin_tran.fin_tran_ref_id instead of ft.fin_tran_ref_id This one is where the error is coming from. Once you fix that, then the one RGlass pointed out in the select list wo...
17307 Aug 2015 @ 09:08 PDTDatabaseReplyQuery Running Slow with Qualify FunctionWhy not keep the session open and just fetch the next 1000 when the user hits the button? Then the query doesn't have to be executed over and over.   The Rownumber function is where the ...
17206 Aug 2015 @ 09:50 PDTPrivate Forum
17124 Jul 2015 @ 02:49 PDTDatabaseReplyALTER PPI - performance impactIt will not uncompress the entire table, only what it needs to look at to perform the operation. In the example above, it would only uncompress the data in the unknown partition to see what if anyt...
17024 Jul 2015 @ 02:47 PDTDatabaseReplySliding Window Merge Join Running for long timeThe query does not specify any relationship between the two tables on the dates in the partitioning of the table. Because there is no relationship specified, a sliding window join must be done to j...
16922 Jul 2015 @ 12:51 PDTDatabaseReplyOptimizing Stats CollectionJust to be complete in this conversation... Disabling this option will disable one of the features of AutoStats. The purpose of this feature is to significantly reduce the cost of stats where samp...
16815 Jul 2015 @ 10:05 PDTToolsReplyWhy TPT mload is taking long time than bteq for huge volume of dataYou haven't described the BTEQ statement that you are comparing to or provided the explain plan for it but I assume since you have the list of rows to delete in tableb that you are doing a...
16708 Jul 2015 @ 10:49 PDTDatabaseReplyQuery Tuning:PPI not being used in selectThe second case requires a full table scan to compute the row_number over all the rows before performing the qualification. PPI doesn't apply when a full scan is required.

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