Date: Tue, 13 Jul 2021 15:21:17 -0400
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Tomas Vondra <tomas.vondra@enterprisedb.com>
Cc: Jeff Davis <pgsql@j-davis.com>, Amit Kapila <amit.kapila16@gmail.com>,
	Euler Taveira <euler@eulerto.com>,
	Greg Nancarrow <gregn4422@gmail.com>,
	Peter Smith <smithpb2250@gmail.com>,
	Rahila Syed <rahilasyed90@gmail.com>,
	Peter Eisentraut <peter.eisentraut@enterprisedb.com>,
	=?utf-8?B?w5ZuZGVyIEthbGFjxLE=?= <onderkalaci@gmail.com>,
	japin <japinli@hotmail.com>, Michael Paquier <michael@paquier.xyz>,
	David Steele <david@pgmasters.net>,
	Craig Ringer <craig@2ndquadrant.com>,
	Tomas Vondra <tomas.vondra@2ndquadrant.com>,
	Amit Langote <amitlangote09@gmail.com>,
	PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: row filtering for logical replication
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On 2021-Jul-13, Tomas Vondra wrote:

> On 7/13/21 5:44 PM, Jeff Davis wrote:

> > * Andres also mentioned that the function should not leak memory.
> > * One use case for this feature is when sharding a table, so the
> > expression should allow things like "hashint8(x) between ...". I'd
> > really like to see this problem solved, as well.
> 
> I think built-in functions should be fine, because generally don't get
> dropped etc. (And if you drop built-in function, well - sorry.)
> 
> Not sure about the memory leaks - I suppose we'd free memory for each row,
> so this shouldn't be an issue I guess ...

I'm not sure we need to be terribly strict about expression evaluation
not leaking any memory here.   I'd rather have a memory context that can
be reset per row.

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/