#DateForumTypeThreadPost
1619 Jan 2012 @ 05:06 PSTDatabaseReplyPlease suggest on an approach to use a STJI First is to figure out why it is skewed. The name MessageId implies something that is faily unique but a fairly unique field should hash and distribute nicely. Since adding Load_Dt to the PI mak...
1521 Dec 2011 @ 07:12 PSTDatabaseReplyData Block Offset within the data block where the first byte of the row sits.
1421 Dec 2011 @ 01:21 PSTDatabaseReplyData Block The data block is read off of disk into memory. The data block contains a list of rowids and offsets into the block that allow access to individual rows. If a single row is being read by hash, t...
1306 Dec 2011 @ 01:40 PSTDatabaseReplyMulti-Value compression has increased the table size There are two limits that apply. There is a maximum number of bytes for the compression values for a single column controlled by the CompresValueList column in TVFields dictionary table (8192 by...
1205 Dec 2011 @ 12:55 PSTDatabaseReplyQuery Caching in Data WarehouseTeradata caches query plans to avoid the cost of parsing and optimizing each time. See Request Cache in the manuals. There are ways to optimize the use if the request cache especially by using par...
1101 Dec 2011 @ 06:28 PSTPrivate Forum
1025 Nov 2011 @ 08:31 PSTDatabaseReplyAn oddity regarding compression on TD 13 Express VMWare edition There was a bug early in 13.10 in this area. If you have not updated 13.10 patches for your installation, you should do so.
924 Nov 2011 @ 07:47 PSTDatabaseReplyhow does we retrieve exact record in case of hash collission Teradata uses rowhash as a general filter but then always compares teh actual value in the row before returning it. While it is correct that a uniqueness value is stored, this is for identif...
823 Nov 2011 @ 02:07 PSTAnalyticsReplyIndex wizard is asking me to Knock of NUPI's created my other "index artists" .. System performance includes update/ETL performance. If there are workloads that were not supplied to index wizard, then it certainly is possible that those workloads might make use of the in...
723 Nov 2011 @ 01:38 PSTDatabaseReplyBest practice for backing up Teradata Table Structures (DLLs)? Teradata's backup facility performing a dictionary/DBC backup is the appropriate way to back up and be able to restore all structures in the database. It will capture not only the objects bu...
623 Nov 2011 @ 12:49 PSTDatabaseReplyNeed clarification on PPI The database would be required to look in all partitions in order to enforce the uniqueness which would be very high cost during insert/update as well as a complex process.
523 Nov 2011 @ 12:46 PSTDatabaseReplyNeed clarification on Parallel Processing means The answer depends on what method/tool you are using to load the data. In general though, what it means is that all AMPs are working on the process of loding simultaneously. Rows with the same P...
423 Nov 2011 @ 11:58 PSTDatabaseReplySegmentation fault(coredump) during executing fastexport script in teradata Please raise an incident with Teradata support.
323 Nov 2011 @ 10:30 PSTGeneralReplyWhat is diff b/w view,non-updatable view,not updatable view See "Updateable views" in SQL Data Definition Language manual.
223 Nov 2011 @ 10:07 PSTPrivate Forum
123 Nov 2011 @ 10:04 PSTPrivate Forum

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