Hi Sayan,
That answers my question only indirectly.
Yes, a given set of keys from TABLEB can be mapped using ORA_HASH() to a
(exact) list of partitions of TABLEA, that contains those keys.
The cross (in my understanding) is that only the Bloom Filter is passed – not
the exact key set from TABLEB.
I can only speculate that along the BF also the list of partitions from TABLEA
that are relevant is passed (constructed as described above) - this is the
point I’d like to clarify.
Kind Regards,
Jaromir D.B. Nemec
<http://www.db-nemec.com> http://www.db-nemec.com
From: Sayan Malakshinov [mailto:xt.and.r@xxxxxxxxx] ;
Sent: Freitag, 16. März 2018 00:29
To: jaromir@xxxxxxxxxxxx
Cc: ORACLE-L <oracle-l@xxxxxxxxxxxxx>
Subject: Re: Bloom Filter Partition Pruning
Jaromir,
That's pretty simple for HASH partitioning:
Oracle can use hashes of elements for BF the same way as it uses them for usual
partition pruning for hash-partitioned tables, so all that we need is just
number of partitions
(https://jonathanlewis.wordpress.com/2009/11/21/ora_hash-function/)
--
Best regards,
Sayan Malakshinov
http://orasql.org
