#DateForumTypeThreadPost
5017 Feb 2011 @ 02:05 PSTDatabaseReplyType Casting in Join...a general rule of thumb is to avoid CAST,COALESCE and CONCATENATION in joins. Optimizer ends up doing internal casting which is time and resource consuming work.
4916 Feb 2011 @ 04:22 PSTDatabaseReplyDBA Admin essential tables and scriptsDBC tables around access rights, operations,data integrity,security etc....DBQL and Resusage tables for user/query and system analysis. Check Teradata manuals for further assistance.
4812 Jan 2011 @ 04:10 PSTDatabaseReplySpool space error in collect statisticsCheck for the data distribution for column combination of COL_B, COL_C, COL_D, COL_E ( using hash function). Also, since spool is used evenly by other ids under profile. make sure that query traff...
4717 Dec 2010 @ 11:42 PSTDatabaseTopicNamed Indexes - Advantages and disadvantagesAs a DBA i have seen practice of using named indexes while table creation in multiple TD shops. One of the advantage is the index maintenance as it makes an entry in DBC.INDICES ,also helping in s...
4607 Dec 2010 @ 04:09 PSTDatabaseReplyIs there a limit to the number of arguments in an "IN" statement?From the mentioned link - 1 MB for SQL request text. It suggest the maximum size limit of a SQL query rather than limiting IN clause values. Therefore, syntax wise you wont have issues with huge I...
4507 Dec 2010 @ 02:36 PSTDatabaseReplyIs there a limit to the number of arguments in an "IN" statement?Not aware of 1MB limit !! where did you get that? Ideally a sub query serve better purpose , performance wise , if the argument list in the IN clause is greater than 50 values though.
4401 Dec 2010 @ 04:17 PSTDatabaseReplyCreate table as..with data...with compression?Though a bit sideline observation but stats do carry over with CREATE TABLE. CT DATABASE_A.TABLE_A AS DATABASE_B.TABLE_B WITH DATA AND STATS;
4319 Nov 2010 @ 02:29 PSTDatabaseReplyFewer Partitions vs Smaller PartitionsI'll suggest you to go with queries retrieval patterns. If the commonly access range is years then it make sense for yearly partition. Between , you can also partition the same table with different...
4203 Nov 2010 @ 04:41 PDTGeneralReplyDifference between Product Join and Cartesian Product JoinI believe Cartesian product join is unconstrained product join , i.e with out join and WHERE clause.
4101 Nov 2010 @ 01:27 PDTUDAReplySQL Query to modify a column datatype lenght.!!!Here are the results while applying above syntax for column's data type change: VARCHAR ( from VARCHAR(20) TO VARCHAR(22)) - successful INTEGER ( FROM INTEGER TO DECIMAL(15,0)) - syntax erro...
4025 Oct 2010 @ 12:01 PDTDatabaseReplyhow to abort session without PEMON or TDManager ?Hi RFiala - Can you provide an example with a session number as 123456 and username as RFiala ?
3919 Oct 2010 @ 10:08 PDTDatabaseReplyHow to find a particular table in Teradata is locked using SQL query?I dont think that you can find such an information with a SQL.Would like to request forum members to share such SQL ,if there is any .Apart from using SHOWLOCK which is a Teradata utility for show...
3812 Sep 2010 @ 05:35 PDTDatabaseReplyCollect Stats - How Performance gets improved?where does the following informations are stored? 1.how many rows per value, 2.is the column indexed, if so unique or non unique etc Does Parsing engine refers to DBC tables for getting stats in...
3709 Sep 2010 @ 03:37 PDTDatabaseReplyCollect Stats - How Performance gets improved?1. Where are these statistics stored? Statistics are stored in DBC views like ColumnStats,IndexStats and MultiColumnStats 2. How does the Parsing Engine use the statistics for t...
3609 Sep 2010 @ 02:22 PDTDatabaseReplySoft RIThanks Dieter..as always ..u rock... I have few additional point to share besides ETL check..These are from DBA perspective.. 1. REFERENCES access right( which is used for soft RI implementat...
3501 Sep 2010 @ 03:34 PDTDatabaseReplySoft RII was inquiring about soft RIs and found above notes. Can some one shed more light on soft RIs ? If data integrity can be guaranteed by ETL ,then soft RI is an impressive feature (even compared ...
3430 Aug 2010 @ 11:50 PDTDatabaseReplySpool treatment for DISTINCT versus GROUP BYWhile browsing Teradata Magazine site ... i came across the following page covering 2009 Teradata R&D Excellence Award's receipt and their contribution. Check out for Ranjan Priyadarshi who has bee...
3325 Aug 2010 @ 03:32 PDTDatabaseReplyIn DBC.sessioninfo table what is the IFPno represents?IFPNo field is the PE Vproc number of the PE to which the session was assigned. For any column definition , you can try doing: HELP OBJECT - such as : HELP VIEW DBC.SESSIONINFO; which in...
3205 Aug 2010 @ 10:39 PDTDatabaseReplySeek clarification for Reserved words Thanks for the response Jim... After your catch, i too revisited the pdf only to observe that all the other KEYWORDS mentioned above apart from SQLTEXT and ROWID are indeed NON-RESERVED KEYWORDS m...
3105 Aug 2010 @ 09:55 PDTDatabaseReplySeek clarification for Reserved words Yes , when i said that iam not getting error with SQLTEXT and ROWID, the sql for them was: SELECT "SQLTEXT" FROM DATABASENAME.TABLENAME; SELECT "ROWID" FROM DATABASENAME.TABLENAME; but using...
3004 Aug 2010 @ 02:34 PDTDatabaseTopicSeek clarification for Reserved words For Teradata 12 - SQL Reference_Fundamentals.pdf , Appendix B contains a list of Restricted Words,Reserved Words and Keywords. Per my knowledge - Teradata database has reserved words that cannot ...
2927 Jul 2010 @ 12:30 PDTDatabaseReplySpool treatment for DISTINCT versus GROUP BYCarlos - Thanks for the information. But seems the distinction between DISTINCT and GROUP BY still exsit as i ran that query on TD 12.
2827 Jul 2010 @ 12:13 PDTDatabaseTopicNon- existing access rights issueBelow query gives me list of tableid which are present in DBC.ACCESSRIGHTS but doesnt exist in DBC.TVM thus ideal candidate to be taken off from DBC.ACCESSRIGHTS. But i need to figure out the use...
2721 Jul 2010 @ 02:31 PDTDatabaseTopicSpool treatment for DISTINCT versus GROUP BYSurprisingly i came across an intresting observation and thoughts of sharing with forum members. On running the following query , i got out of spool space error 2646: SELECT DISTINCT OBJECTT...
2612 Jul 2010 @ 11:40 PDTDatabaseReplyLockingHi Bodhi - Kind advice - for any new question ,start a new thread. Its beneficial for you and anyone who is seeking similar answers. On your question - Here is a briefing: There are four types ...

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