From: Josh Berkus <josh@agliodbs.com>
To: Christian Weyer <christian.weyer@thinktecture.com>
To: pgsql-performance@postgresql.org <pgsql-performance@postgresql.org>
Subject: Re: Unexpected (bad) performance when querying indexed JSONB column
Date: Sun, 01 Feb 2015 13:06:23 -0800
Message-ID: <54CE954F.7070904@agliodbs.com> (raw)
In-Reply-To: <WM!3b9b688279bfaf852b09eb38e12d59633671a1b1dacc67e4f7be92553c116d3655cd62355ebe242eb4ae45275d2a5848!@asav-2.01.com>
References: <7F9BEAD7-C190-4E21-8240-04687FA88435@thinktecture.com>
<WM!3b9b688279bfaf852b09eb38e12d59633671a1b1dacc67e4f7be92553c116d3655cd62355ebe242eb4ae45275d2a5848!@asav-2.01.com>
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On 01/31/2015 11:02 AM, Christian Weyer wrote:
> Just checked: the execution time is the same when I drop the index.
>
> Execution plan with index:
> ---
> "Bitmap Heap Scan on articles (cost=16.25..135.64 rows=33 width=427)"
> " Recheck Cond: (data @> '{"locked": true}'::jsonb)"
> " -> Bitmap Index Scan on idx_data (cost=0.00..16.24 rows=33 width=0)"
> " Index Cond: (data @> '{"locked": true}'::jsonb)"
> ---
>
> And without the index:
> ---
> "Seq Scan on articles (cost=0.00..2289.21 rows=33 width=427)"
> " Filter: (data @> '{"locked": true}'::jsonb)"
> ---
Please send us the output of EXPLAIN ( ANALYZE ON, BUFFERS ON ) so that
we can see what the query is actually doing, rather than just what the
plan was.
--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com
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To: pgsql-performance@postgresql.org
Cc: josh@agliodbs.com, christian.weyer@thinktecture.com
Subject: Re: Unexpected (bad) performance when querying indexed JSONB column
In-Reply-To: <54CE954F.7070904@agliodbs.com>
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