Single Value Column Frequency Histogram Oracle 12c and later
It is hopefully in the meantime well known that Oracle has introduced in version 11g a new algorithm to gather statistics on a table that no longer requires sorting for determining the critical Number...
View Article12.2.0.1 And Later Support (Limited) Extended Stats On Virtual columns /...
I do have a demo as part of my optimizer related workshops that shows the restriction / limitation of DBMS_STATS not supporting extended statistics on virtual columns / group of expressions, so for...
View ArticleNew Parallel Distribution Method For Direct Path Loads
Starting with version 12c Oracle obviously has introduced another parallel distribution method for direct path loads (applicable to INSERT APPEND and CTAS operations) when dealing with partitioned...
View ArticleOracle 12c – pre-built join index
By Franck Pachot. This post is part of a series of small examples of recent features. I’m running this in the Oracle 20c preview in the Oracle Cloud. I have created a few tables in the previous post...
View ArticleOracle 12c – peak detection with MATCH_RECOGNIZE
By Franck Pachot. This post is part of a series of small examples of recent features. I’m running this in the Oracle 20c preview in the Oracle Cloud. I’ll show a very basic example of “Row Pattern...
View ArticleOracle 12c – reorg and split table with clustering
By Franck Pachot. In this series of small examples on recent features, I have imported in a previous post, the statistics of covid-19 per day and per countries. This is typical of data that comes as a...
View ArticleOracle 12c – global partial index
By Franck Pachot. We have an incredible number of possibilities with Oracle. Yes, an index can be global (indexing many partitions without having to be partitioned itself on the same key) and partial...
View ArticleAWR Flush Levels
From version 12.1.0.2 onward, for taking AWR snapshots, you have the choice between four AWR flush levels: BESTFIT, LITE, TYPICAL and ALL. If you check the Oracle Database documentation, you won’t find...
View ArticleAWR: Multitenant-Specific Initialization Parameters
By default, the database engine automatically takes snapshots in the root container only. Such snapshots cover the root container as well as all open PDBs belonging to it. From version 12.2 onward, you...
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