Re: Re: Enabling checksums on a streaming replica

2019-06-26 Thread Brad Nicholson
Grigory Smolkin wrote on 06/26/2019 12:37:10 PM: > From: Grigory Smolkin > To: pgsql-general@lists.postgresql.org > Date: 06/26/2019 12:37 PM > Subject: [EXTERNAL] Re: Enabling checksums on a streaming replica > > Hello! > Very interesting idea, but what about full page writes, that comes >

Re: Enabling checksums on a streaming replica

2019-06-26 Thread Grigory Smolkin
Hello! Very interesting idea, but what about full page writes, that comes from master? Can they be a problem? On 6/26/19 6:32 PM, Brad Nicholson wrote: I'm wondering about the validity of using the pg_checksums utility to enable checksum's on a streaming replication standby, and then

Re: REINDEX : new parameter to preserve current average leaf density as new implicit FILLFACTOR

2019-06-26 Thread Peter Geoghegan
On Wed, Jun 26, 2019 at 8:05 AM John Lumby wrote: > > There is a very recent research paper that discusses the idea of > > varying fillfactor with a view to ameliorating page splits: > > > > Thanks, I am chewing my way through that. As you say, it does address > exactly the issues I raised. >

Enabling checksums on a streaming replica

2019-06-26 Thread Brad Nicholson
I'm wondering about the validity of using the pg_checksums utility to enable checksum's on a streaming replication standby, and then promoting that standby as a way to enable checksums on existing clusters. I've tested the process out, and it "works" (by works I mean doesn't blow up or log any

pg_receivelwal vs synchronous

2019-06-26 Thread Jesper Pedersen
Hi, PostgreSQL 11.4 Given, postgresql.conf: wal_level = replica synchronous_commit = remote_apply synchronous_standby_names = '*' CREATE ROLE repluser WITH LOGIN REPLICATION PASSWORD 'mypwd'; SELECT pg_create_physical_replication_slot('replica1'); Execute pg_receivewal -D

Re: REINDEX : new parameter to preserve current average leaf density as new implicit FILLFACTOR

2019-06-26 Thread John Lumby
Thanks Tom and Peter for those thoughts. > > I think you've confused REINDEX with VACUUM. It seems like a pretty poor > substitute for that --- it's much more expensive and has worse locking > requirements. > I think the answer is mainly "I wish it were so" , but in practice, even with a

Re: How to return ARRAY from SQL function?

2019-06-26 Thread Alexander Farber
Thank you - On Tue, Jun 18, 2019 at 3:10 PM Tom Lane wrote: > Alexander Farber writes: > > And then I shuffle the letters by - > > > CREATE OR REPLACE FUNCTION words_shuffle(in_array text[]) > > RETURNS text[] AS > > $func$ > > SELECT array_agg(x ORDER BY RANDOM()) FROM

RE: Max_connections limit

2019-06-26 Thread Ahmed, Nawaz (Fuji Xerox Australia)
Hi, If you reckon the application initiates such a large number of concurrent connections, I'd suggest you configure a connection pooler to avoid the connection overhead by PostgreSQL. max_connections will be the parameter you are looking at to configure but ensure it is configured in

Max_connections limit

2019-06-26 Thread Daulat Ram
Hello team, We have migrated our database from Oracle 12c to Postgres 11. I need your suggestions , we have sessions limit in Oracle = 3024 . Do we need to set the same connection limit in Postgres as well. How we can decide the max_connections limit for postgres. Are there any differences in