From: PG Doc comments form <noreply@postgresql.org>
To: pgsql-docs@lists.postgresql.org
Cc: holger.vornholt@deutschebahn.com
Subject: Documentation on Hash and btree Indexes on jsonb
Date: Sat, 13 Feb 2021 09:37:19 +0000
Message-ID: <161320903985.3454.7956608521954674568@wrigleys.postgresql.org> (raw)
The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/13/datatype-json.html
Description:
Hello everyone,
we are planning to test postgres as a nosql database for streaming kafka
events (converted to jsonb) into it next week.
Therefore I am researching on index types. We would mostly be using queries
like message @> '{"fahrtnummer": "37458"}' or message ->> 'fahrtnummer' =
'37458' respectively. Where fahrtnummer always exists and is not an array.
The documentation on https://www.postgresql.org/docs/12/datatype-json.html
claims:
"jsonb also supports btree and hash indexes. These are usually useful only
if it's important to check equality of complete JSON documents."
According to some older information from 2016
https://bitnine.net/blog-postgresql/postgresql-internals-jsonb-type-and-its-indexes/?ckattempt=1https://stackoverflow.com/questions/36075918/postgresql-index-on-json
it seems to be a valid option to use hash or btree indexes in that case
however.
"As a result, in the choice of an index for JSONB type, if the index
searches a few predetermined attributes, BTREE is the best choice"
The quoted sentance from the postgres documentation would suggest, that this
option could be discarded. I would love to hear your feedback on this
matter.
Thank you!
Holger
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Subject: Re: Documentation on Hash and btree Indexes on jsonb
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