Re: Access and Filter Predicate on same execution plan line
From: Mladen Gogala <gogala.mladen_at_gmail.com>
Date: Tue, 17 Aug 2021 14:22:05 -0400
Message-ID: <bd9b9db8-3b0b-669d-c861-ab42fe33c3a8_at_gmail.com>
Date: Tue, 17 Aug 2021 14:22:05 -0400
Message-ID: <bd9b9db8-3b0b-669d-c861-ab42fe33c3a8_at_gmail.com>
To tell the truth, skip scan is far from ideal. It is similar to fast full index scan. It reads all the values of the first column and then returns the rows with requested values of the 2nd column.
What Oracle would need is this:https://www.percona.com/blog/2019/06/14/bloom-indexes-in-postgresql/
On 8/17/21 2:05 PM, Powell, Mark wrote:
Amit, Oracle can use a multi-column index even if the first column in the index is not used in a WHERE clause condition if the optimizer thinks doing so in a benefit. If you have access to Oracle Support, you can read the following document for a little bit of information on the feature. More than likely there are only a few distinct values for the leading column for this feature to be invoked.Index Skip Scan Feature (Doc ID 212391.1)
Mark PowellDatabase Administration(313) 592-5148
-- Mladen Gogala Database Consultant Tel: (347) 321-1217 https://dbwhisperer.wordpress.com-- http://www.freelists.org/webpage/oracle-l Received on Tue Aug 17 2021 - 20:22:05 CEST