pscbo_stats sample size
Hi,
Note 1322888.1 states: “Speed of Sampling - In Oracle 10g, the sample size is altered as a function of table size in order to improve the execution speed while still gathering meaningful statistics. The Auto Sample Size algorithm is used in Oracle 11g since it represents an excellent balance between speed and accuracy. If a histogram is defined for any table in either version, the sample size is changed to 100% to ensure quality of sample.”
However, I have inserted several columns for PS_TRANSACTION_INV into table PSCBO_HISTOGRAM_COLS, which according to that note means Oracle should use a 100% sample size, right? Well, that is not happening. When I invoke PSCBO_STATS.GATHER_TABLE_STATS('PS_TRANSACTION_INV') I see in the log table (PSCBO_LOG) that Oracle is using 30%, not 100%.
Note 1322888.1 states: “Speed of Sampling - In Oracle 10g, the sample size is altered as a function of table size in order to improve the execution speed while still gathering meaningful statistics. The Auto Sample Size algorithm is used in Oracle 11g since it represents an excellent balance between speed and accuracy. If a histogram is defined for any table in either version, the sample size is changed to 100% to ensure quality of sample.”
However, I have inserted several columns for PS_TRANSACTION_INV into table PSCBO_HISTOGRAM_COLS, which according to that note means Oracle should use a 100% sample size, right? Well, that is not happening. When I invoke PSCBO_STATS.GATHER_TABLE_STATS('PS_TRANSACTION_INV') I see in the log table (PSCBO_LOG) that Oracle is using 30%, not 100%.
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