Re: row filtering for logical replication

On 23/11/2018 17:39, David Fetter wrote:
> On Fri, Nov 23, 2018 at 12:03:27AM +0100, Petr Jelinek wrote:
>> On 01/11/2018 01:29, Euler Taveira wrote:
>>> Em qua, 28 de fev de 2018 às 20:03, Euler Taveira
>>> <euler(at)timbira(dot)com(dot)br> escreveu:
>>>> The attached patches add support for filtering rows in the publisher.
>>>>
>>> I rebased the patch. I added row filtering for initial
>>> synchronization, pg_dump support and psql support. 0001 removes unused
>>> code. 0002 reduces memory use. 0003 passes only structure member that
>>> is used in create_estate_for_relation. 0004 reuses a parser node for
>>> row filtering. 0005 is the feature. 0006 prints WHERE expression in
>>> psql. 0007 adds pg_dump support. 0008 is only for debug purposes (I'm
>>> not sure some of these messages will be part of the final patch).
>>> 0001, 0002, 0003 and 0008 are not mandatory for this feature.
>>
>> Hi,
>>
>> I think there are two main topics that still need to be discussed about
>> this patch.
>>
>> Firstly, I am not sure if it's wise to allow UDFs in the filter clause
>> for the table. The reason for that is that we can't record all necessary
>> dependencies there because the functions are black box for parser.
>
> Some UDFs are not a black box for the parser, namely ones written in
> SQL. Would it make sense at least not to foreclose the non-(black box)
> option?
>

Yeah inlinable SQL functions should be fine, we just need the ability to
extract dependencies.

--
Petr Jelinek http://www.2ndQuadrant.com/
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