postgres.git / summary / log / commit / refs

commit    e7a6cd5dcf24c6d4b04d036a4837c7af154c4b49
Author:   Bruce Momjian <bruce@momjian.us>
Date:     Mon Aug 03 21:01:42 2020 +0000
First released in: 13.0

    doc:  PG 13 relnotes: hash_mem_multiplier can restore old behav.
    
    Document that hash_mem_multiplier can get query behavior closer to the
    pre-PG 13 behavior of allowing hashing to use more memory.
    
    Reported-by: Peter Geoghegan
    
    Discussion: https://postgr.es/m/CAH2-Wzn3kwQm_pe6g2=ki+P7+ZRqH5GvFGn6SWfv_j7UUgcLdQ@mail.gmail.com
    
    Backpatch-through: 13 only


 doc/src/sgml/release-13.sgml | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/doc/src/sgml/release-13.sgml b/doc/src/sgml/release-13.sgml
index 18e6497a7f2..0b1051ba824 100644
--- a/doc/src/sgml/release-13.sgml
+++ b/doc/src/sgml/release-13.sgml
@@ -649,7 +649,10 @@ Author: Jeff Davis <jdavis@postgresql.org>
 
        <para>
         Previously, hash aggregation was avoided if it was expected to use
-        more than <xref linkend="guc-work-mem"/> memory.
+        more than <xref linkend="guc-work-mem"/> memory.  To reduce the
+        likelihood of using disk storage for hash aggregation and attain
+        behavior similar to previous Postgres releases, increase <xref
+        linkend="guc-hash-mem-multiplier"/>.
        </para>
       </listitem>
 


[parent: 72ca61101ad4]