Re: dirty_ratio & dirty_background_ratio settings with huge memory

2018-03-06 Thread Tomas Vondra
m.dirty_background_bytes and 1 GB for vm.dirty_bytes sounds fine. > It should be the other way around: dirty_background_bytes < dirty_bytes regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: Postgresql 10.3 , query never completes if LIMIT clause is specified and paralle processing is on

2018-03-21 Thread Tomas Vondra
ircuit_layout cl ON cl.segment_id = sg.id <http://sg.id> AND cl.ordinal > = 1 > JOIN circuit c ON c.id <http://c.id> = cl.circuit_id > JOIN vendor v ON v.id <http://v.id> = c.pop_support_vendor_id > ) seg ON seg.circuit_id = c.id <http://c.id> > JOIN vendor_gtt_pop on vendor_gtt_pop.g

Re: Postgresql 10.3 , query never completes if LIMIT clause is specified and paralle processing is on

2018-03-21 Thread Tomas Vondra
re a self-contained test case that we might use to reproduce the issue? For example by dumping the relevant part of the tables? regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: Postgresql 10.3 , query never completes if LIMIT clause is specified and paralle processing is on

2018-03-22 Thread Tomas Vondra
nd share the report.txt with us (well, if it's very large you may need to only cut the first 1000 lines or so). That should tell us in which functions most of the time is spent. That will give us some hints, hopefully. > > For what concerns the  self-contained test case -

Re: Postgresql 10.3 , query never completes if LIMIT clause is specified and paralle processing is on

2018-03-22 Thread Tomas Vondra
On 03/22/2018 11:29 PM, Alessandro Aste wrote: > Thanks Tomas. We're currently building postgres from source. In order to > enable symbols, you want me to re-configure postres with  --enable-debug > then run perf? > Yes. regards -- Tomas Vondra http://ww

Re: Postgresql 10.3 , query never completes if LIMIT clause is specified and paralle processing is on

2018-03-28 Thread Tomas Vondra
>   > > *Time: 2245.073 ms (00:02.245)* > > > > > On Fri, Mar 23, 2018 at 9:31 AM, Alessandro Aste > mailto:alessandro.a...@gmail.com>> wrote: > > Tomas, I'm attaching a 4MB file with the perf report. Let me > know

Re: Seems like there is an issue with reltuples showing twice the number of rows

2018-04-03 Thread Tomas Vondra
tuples to rather different estimates. That is fixed now and should be in the next minor release. Hard to say if this is a case of that, but judging by the number of dead tuples chances are it is. It's probably better to use n_live_tup instead, though. I'd say that's closer to th

Re: ERROR: found multixact from before relminmxid

2018-04-06 Thread Tomas Vondra
t the data pages it's nearly impossible to determine what went wrong. We'd also need more information about what happened to the hardware and cluster before the issues started to appear - crashes, hardware issues. And so on. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: ERROR: found multixact from before relminmxid

2018-04-06 Thread Tomas Vondra
On 04/06/2018 04:29 PM, Alexandre Arruda wrote: > 2018-04-06 9:39 GMT-03:00 Tomas Vondra <mailto:tomas.von...@2ndquadrant.com>>: > > > > On 04/06/2018 02:09 AM, Alexandre Arruda wrote: > > Hi, > > > > Some time ago, I had this e

Re: ERROR: found multixact from before relminmxid

2018-04-09 Thread Tomas Vondra
On 04/09/2018 01:49 PM, Alexandre Arruda wrote: > > > 2018-04-06 13:11 GMT-03:00 Tomas Vondra <mailto:tomas.von...@2ndquadrant.com>>: > > > > On 04/06/2018 04:29 PM, Alexandre Arruda wrote: > > 2018-04-06 9:39 GMT-03:00 Tomas Vondra

Re: Shared buffers increased but cache hit ratio is still 85%

2018-07-18 Thread Tomas Vondra
be granted to others.)|| > It might be better to note current values of the counters somewhere, and compute a delta later (and use that to compute the cache hit ratio). The issue is that pg_stat_reset() throws away all sorts of interesting and important stats, including those driving autovacuum/a

Re: is there any adverse effect on DB if I set autovacuum scale factor to zero?

2018-08-13 Thread Tomas Vondra
be due to all the autovacuum workers being constantly busy, unable to cleanup all tables in a timely manner. In that case lowering the threshold is not going to help, on the contrary. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: is there any adverse effect on DB if I set autovacuum scale factor to zero?

2018-08-13 Thread Tomas Vondra
/ more often, so it may have adverse impact, of course. It's hard to say if it's going to be a win overall, because we don't know how serious is the bloat. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: Fwd: is there any adverse effect on DB if I set autovacuum scale factor to zero?

2018-08-13 Thread Tomas Vondra
e done per second. Increasing the number of workers is akin to allowing more cars on a highway, but also lowering the speed limit. You need to increase the limit on amount of work, and lowering naptime is one way to do that. regards -- Tomas Vondra http://www.2ndQuadra

Re: Code of Conduct

2018-09-18 Thread Tomas Vondra
of the people involved in both groups I'm not worried about this part. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: Help to understand Actual Rows vs Plan Rows from the query planner output

2018-09-23 Thread Tomas Vondra
t;Bitmap Index Scan” on “users_lower_idx”, I > see the plan rows are 50, but actual rows it got 1. In the second node > type of "Bitmap Index Scan” on “ lower_state_users_idx”, I see the plan > rows are 211, and actual rows 211. Both are same. Based on what > conditions pl

Re: Why the index is not used ?

2018-10-07 Thread Tomas Vondra
does not really solve the issues with having to pass the password to the query, making it visible in pg_stat_activity, various logs etc. Which is why people generally use FDE for the whole disk, which is transparent and provides the same level of protection. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: Why the index is not used ?

2018-10-08 Thread Tomas Vondra
s discussion, it does not seem very polished / resilient. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: COPY command returns "ERROR: invalid XML content"

2019-10-07 Thread Tomas Vondra
? regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: Install postgres on rhel 7

2019-10-07 Thread Tomas Vondra
. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: PG 12 not yet for mac

2019-10-07 Thread Tomas Vondra
x27;s not a project/page managed by the PostgreSQL community, you need to report the issues to the authors (most likely through github issues). regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: pgcrypto question

2019-10-07 Thread Tomas Vondra
eems like an interesting idea - I wonder if it could be done e.g. in psycopg as an extension, or something like that. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: pgcrypto question

2019-10-07 Thread Tomas Vondra
7;s no easy way to distinguish them. I'm no psycopg2 expert, but it does have some infrastructure for casting PostgreSQL types to Python types, and I guess that could be used for the encryption. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development,

Re: temporary files

2019-10-07 Thread Tomas Vondra
size. That seems as if a single query was executed repeatedly. Maybe try looking into what query that is. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: Table locking during backup

2019-10-07 Thread Tomas Vondra
ystem view. And it does conflict with the ACCESS EXCLUSIVE mode, used by the second query. Could you suggest me which part of pg_dump (which query) might cause that behaviour. It's this line: https://github.com/postgres/postgres/blob/master/src/bin/pg_dump/pg_dump.c#L6676 regards -- To

Re: timescaleDB & WAL replication

2019-10-15 Thread Tomas Vondra
timescaleDB extention on the master side? AFAIK timescale is "just" a regular extension, in which case yes, all you need to do is installing it on the master side. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA

Re: jsonb_set() strictness considered harmful to data

2019-10-19 Thread Tomas Vondra
all. I do mostly agree with this. The json[b]_set behavior seems rather surprising, and I think I've seen a couple of cases running into exactly this issue. I've solved that with a simple CASE, but maybe changing the behavior would be better. That's unlikely to be back-patchable, though, so maybe a better option is to create a non-strict wrappers. But that does not work when the user is unaware of the behavior :-( regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: Replication of Replication

2019-10-19 Thread Tomas Vondra
topped, etc. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: releasing space

2019-10-19 Thread Tomas Vondra
rsions (~30 months) of fixes behind. You might want to consider upgrading ... -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: Has there been any discussion of custom dictionaries being defined in the database?

2019-10-19 Thread Tomas Vondra
#x27;t think that's entirely necessary, thoug - we could use the table directly. Yes, that would be slower, but maybe it'd be sufficient. But I think the idea is ultimately that we'd implement a new dict type in core, and people would just specify which table to load data

Re: jsonb_set() strictness considered harmful to data

2019-10-19 Thread Tomas Vondra
ot;...", NULL) should do the same thing as jsonb_set(..., "...", 'null':jsonb) I'm not entirely surprised it's what MySQL does ;-) but I'd say treating it as a deletion of the key (just like MSSQL) is somewhat more sensible. But I admit it's quit

Re: jsonb_set() strictness considered harmful to data

2019-10-19 Thread Tomas Vondra
ferently. And at the same time one can argue, that people, who are not aware about this caveat with jsonb_set and NULL values, will most likely use it due to a bit simpler syntax (more similar to some popular programming languages). This seems like an entirely independent thing ... Right. Useful,

Re: jsonb_set() strictness considered harmful to data

2019-10-19 Thread Tomas Vondra
On Sat, Oct 19, 2019 at 12:47:39PM -0400, Andrew Dunstan wrote: On 10/19/19 12:32 PM, David G. Johnston wrote: On Sat, Oct 19, 2019 at 9:19 AM Tomas Vondra mailto:tomas.von...@2ndquadrant.com>> wrote: > >We invented jsonb_set() (credit to Dmitry Dolgov). And we've

Re: releasing space

2019-10-19 Thread Tomas Vondra
or version upgrade. FWIW Julie, please don't top post - it just makes it harder to follow the discussion. Also, this seems like a completely separate question, unrelated to the DROP DATABLASE one. It might be better to start a new thread instead of repurposing an existing one. regards

Re: jsonb_set() strictness considered harmful to data

2019-10-20 Thread Tomas Vondra
onb_set and NULL in the archives), but I'm not sure that's enough to justify any changes in backbranches. I'd say no, but I have no idea how many people are affected by this but don't know about it ... regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: CPU SPIKE

2019-10-20 Thread Tomas Vondra
execution is using CPU, so yes - it can cause a spike in CPU usage. The question is whether the query plan is efficient, or whether it's using the CPU unenecessarily. You need to show us EXPLAIN ANALYZE and perhaps explain why you think it shouldn't use this much CPU. regards -- To

Re: jsonb_set() strictness considered harmful to data

2019-10-20 Thread Tomas Vondra
On Sun, Oct 20, 2019 at 06:51:05PM -0400, Andrew Dunstan wrote: On 10/20/19 4:18 PM, Tomas Vondra wrote: On Sun, Oct 20, 2019 at 03:48:05PM -0400, Andrew Dunstan wrote: On 10/20/19 1:14 PM, David G. Johnston wrote: On Sun, Oct 20, 2019 at 5:31 AM Andrew Dunstan mailto:andrew.duns

Re: jsonb_set() strictness considered harmful to data

2019-10-21 Thread Tomas Vondra
On Mon, Oct 21, 2019 at 08:06:46AM -0700, Adrian Klaver wrote: On 10/20/19 11:07 PM, Tomas Vondra wrote: On Sun, Oct 20, 2019 at 06:51:05PM -0400, Andrew Dunstan wrote: True. And AFAIK catching exceptions is not really possible in some code, e.g. in stored procedures (because we can'

Re: Barman

2019-10-31 Thread Tomas Vondra
io 1" in the barman docs, i.e. pg_basebackup (backup_method = postgres) and WAL streaming. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: How to import Apache parquet files?

2019-11-05 Thread Tomas Vondra
ed and probably significantly less efficient than COPY. So if you have a lot of these parquet files, I'd probably use the COPY. But maybe the ability to query the parquet files directly (with FDW) is useful for you. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Devel

Re: BigSQL pgc alternative

2019-12-21 Thread Tomas Vondra
ly you mean when you say "portable option". Can you explain? regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: jsonb_set() strictness considered harmful to data

2020-01-17 Thread Tomas Vondra
warnings check-world passed without any problems I'll mark this patch as ready for commiter Thank you for your work Thanks for the review. I propose to commit this shortly. Now that this was committed, I've updated the patch status accordingly. Thanks! -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: Avoiding out of date statistics / planner

2020-02-12 Thread Tomas Vondra
rming the root cause - you'll see the query plan, which should give you enough context. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: 1 Status of vertical clustered index - 2 Join using (fk_constraint) suggestion - 3 Status of pgsql's parser autonomization

2020-02-16 Thread Tomas Vondra
cases you're thinking about? FWIW I think it's pretty bad idea to post questions about three very different topics into a single pgsql-hackers thread. That'll just lead to a lot of confusion. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: DB running out of memory issues after upgrade

2020-02-18 Thread Tomas Vondra
ed) and do (gdb) p MemoryContextStats(TopMemoryContext) (gdb) q and show us the output printed into server log. If it's a backend running a query, it'd help knowing the execution plan. It would also help knowing the non-default configuration, i.e. stuff tweaked in postgresql.conf. rega

Re: Check constraints do not seem to be working!!!

2020-11-11 Thread Tomas Vondra
(b it not null and b = true) and (c is not null) Or something like that. regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: Extended statistics for correlated columns, row estimates when values are not in MCVs list

2020-12-07 Thread Tomas Vondra
es. That should consider the column-level correlation even when the combination of values is not in the MCV. It might make the "good" estimate worse, but that's an inherent trade-off. regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: Potential BRIN Index Corruption

2020-12-09 Thread Tomas Vondra
s generated per day, or something like that. Maybe there was some I/O issue in that time period and a couple writes got lost, or something like that. Are there any other corrupted indexes on the table? regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: Is there a way to dump schema to files on disk and keep them in sync

2020-12-13 Thread Tomas Vondra
chema versioning tools available - we have a list on the wiki: https://wiki.postgresql.org/wiki/Change_management_tools_and_techniques I'm sure it's incomplete, but it's helpful nevertheless. regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: PostgreSQL 14.4 ERROR: out of memory issues

2022-07-14 Thread Tomas Vondra
gt; I think it's be interesting to get memory context stats from the processes consuming a lot of memory. If you know which processes are suspect (and it seems you know, bacause if a reconnect helps it's the backend handling the connection), you can attach a debugger and do $ gdb -p $PID call MemoryContextStats(TopMemoryContext) which will log info about memory contexts, just like autovacuum. Hopefully that tells us memory context is bloated, and that might point us to particular part of the code. regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: Expr. extended stats are skipped with equality operator

2022-08-07 Thread Tomas Vondra
it could be build-dependent > and a bit hard to track down if one doesn't control the build flags > Yeah, this seems like a clear bug - we should not fail queries like this. It's a sign statext_is_compatible_clause() and the MCV code disagrees which clauses are compatible. Can you share an example triggering this? regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: Expr. extended stats are skipped with equality operator

2022-08-07 Thread Tomas Vondra
On 8/7/22 19:28, Tom Lane wrote: > Tomas Vondra writes: >> Yeah, this seems like a clear bug - we should not fail queries like >> this. It's a sign statext_is_compatible_clause() and the MCV code >> disagrees which clauses are compatible. > > Indeed. I at

Re: backend crash on DELETE, reproducible locally

2018-11-06 Thread Tomas Vondra
ticular thing makes it less extensible? That being said, we also have RELOPT_KIND_BRIN, and that seems to be missing from RELOPT_KIND_INDEX too (and AFAICS the optimization works for all index types). regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: integrate Postgres Users Authentication with our own LDAP Server

2019-05-09 Thread Tomas Vondra
right thing is to send it to pgsql-general. Likewise, it makes little sense to send questions to the "owner". I've removed the other lists from CC. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: Question regarding specifics of GIN and pg_trgm performance and potential use of show_trgm to improve it

2023-05-25 Thread Tomas Vondra
         Index Cond: (value % 'lorem'::text) >          Buffers: shared hit=109 >  Planning: >    Buffers: shared hit=3 >  Planning Time: 2.394 ms >  Execution Time: 2273.256 ms > (13 rows) > > > Thank you for any sort of insight into this.

Re: pb with join plan

2023-06-21 Thread Tomas Vondra
e you into what to do instead. > >   > I know that page. obviously, as I have to kill the request, I cannot > provide a explain analyze...  > It's a bit weird the "victor" table is joined seemingly without any join conditions, leading to a cross join (which massively inflates the cost for joins above it). Maybe the anonymized plan mangles it somehow. regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: move databases from a MySQL server to Postgresql.

2023-06-23 Thread Tomas Vondra
questions about practical issues you run ran into. regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: [Beginner Question]What is query jumbling?

2023-07-17 Thread Tomas Vondra
jumble. So "jumbling" is a process to generate a "normalized" query. regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: Query take a long time and use no index

2023-07-17 Thread Tomas Vondra
the DATE_TRUNC. > How can I optimize? > It's always going to be slow with the COUNT(DISTINCT), I'm afraid. Not sure how much you can modify the query / database, and how accurate results you need. If you're OK with estimates, you can try postgres-hll extension [2] which estimates count(distinct). For exact reaults, I wrote count_distinct extension [2] that uses hashtable. Might be worth a try, I guess. Another option is to precalculate stuff, and do queries on that. That is, you're not going to add data with old timestamps, so you can pre-aggregate that. regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: Query take a long time and use no index

2023-07-17 Thread Tomas Vondra
On 7/17/23 13:20, Tomas Vondra wrote: > ... > > It's always going to be slow with the COUNT(DISTINCT), I'm afraid. > > Not sure how much you can modify the query / database, and how accurate > results you need. If you're OK with estimates, you can try postgres-hl

Re: How to grant read only functions execute permission to read only user

2023-07-17 Thread Tomas Vondra
ege), then the function can't do any writes either. regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: Intermittent Issue with WAL Segment Removal in Logical Replication

2023-12-29 Thread Tomas Vondra
n for the replication slot peerflow_slot_wal_testing_2 (especially the restart_lsn value). Also, maybe show the contents of pg_wal (especially for the segment referenced in the error message). Can you reproduce this outside Google cloud environment? regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: Intermittent Issue with WAL Segment Removal in Logical Replication

2023-12-29 Thread Tomas Vondra
debug > this further? > Hard to say. The best thing would be to have a reproducer script, ofc. If that's not possible, the information already requested seems like a good start. regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: How do you optimize the disk IO when you cannot assume a file will start at a boundary then?

2024-02-22 Thread Tomas Vondra
ter. The postgres 8kB page? The filesytem page? The storage block/sector size? FWIW I think for SSDs this matters way more than for HDD, because SSDs have to erase the space before a rewrite, which makes it much more expensive. But that's not just about the alignment, but about the page size

Re: Performance degradation after upgrading from 9.5 to 14

2024-04-17 Thread Tomas Vondra
rade? 3) Did you transfer the configuration, or did you just create a new cluster with the default values? 4) What exactly is slower? Queries? Inserts? 5) Can you quantify the impact? Is it 2x slower? 100x slower? regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: Unexpected data when subscribing to logical replication slot

2024-05-08 Thread Tomas Vondra
t to "off". > > We need help to understand this unexpected behaviour. > Would be good to have some sort of reproducer - ideally a script that sets up an instance + replication, and demonstrates the issue. Or at least a sufficiently detailed steps to reproduce it without having to guess what exactly you did. regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: page is not marked all-visible but visibility map bit is set in relation "pg_statistic"

2024-07-11 Thread Tomas Vondra
igate issues on a proprietary product. regards [1] https://www.postgresql.org/message-id/CAH2-WznuNGSzF8v6OsgjaC5aYsb3cZ6HW6MLm30X0d65cmSH6A%40mail.gmail.com -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: PG Dump on 11 - Restore on 16 - is possible?

2024-08-13 Thread Tomas Vondra
ion 9.2 are supported.) I'd probably use pg_dump from the target version (PG16), but it should not matter. regards -- Tomas Vondra

Re: About replication minimal disk space usage

2024-08-24 Thread Tomas Vondra
g ends up spilling the decoded transaction to disk. If you want a better answer, I think you'll have to provide a lot more details. For example, which PostgreSQL version are you using, and how is it configured? What config parameters have non-default values? regards -- Tomas Vondra

Re: ERROR: could not open relation with OID XXXX

2024-08-25 Thread Tomas Vondra
es it easier to hit, but it can happen without it. > Is there something I can do to avoid this? Is my understanding of how > the catalog tables work wrong? > I believe you could actually lock the pg_class rows for update. Just add FOR UPDATE at the end of the query. regards -- Tomas Vondra

Re: ERROR: could not open relation with OID XXXX

2024-08-25 Thread Tomas Vondra
ve no idea what you mean - what would be filtered out, etc. But you can give it a try - you have a reproducer, so testing if it fails should not be that difficult. Other than that, I think you can do two things: 1) Make the application to simply retry in it sees this error. 2) Lock the objects using LOCK TABLE before running the query. regards -- Tomas Vondra

Re: BRIN index on timestamptz

2021-04-23 Thread Tomas Vondra
dom data, because the whole idea is about eliminating large blocks of data (e.g. 1MB). But with random data that's not going to happen, because each such range will match anything. Which is why seqscan is a bit faster than when using BRIN index. regards -- Tomas Vondra EnterpriseDB: http:

Re: Extended stats - value not in MCV list

2021-05-04 Thread Tomas Vondra
of the columns, in which case we don't know how many groups we actually matched, etc. TBH I'm not sure how much of those implementation details we want to put into the user docs - it may be a bit too much, and we may need to change some of it. regards -- Tomas Vondra EnterpriseDB

Re: Strange behavior of function date_trunc

2021-05-05 Thread Tomas Vondra
On 5/5/21 3:23 PM, Pavel Luzanov wrote: Hello, It is very likely that the date_trunc function in the following example is executed for each line of the query. Although it marked as a STABLE and could only be called once. It could, but that's just an option - the database may do that, bu

Re: How to hash a large amount of data within Postgres?

2021-06-23 Thread Tomas Vondra
rfaces to read chunks of data from large objects - see this: 1) lo_get (loid, offset, length) https://www.postgresql.org/docs/13/lo-funcs.html 2) lo_seek() + lo_read() https://www.postgresql.org/docs/13/lo-interfaces.html Obviously, you can't do "loread(fd, size)" because that's going to attempt building one large bytea, failing because of the alloc limit. You have to stream the data into the hash. Doing that in plpgsql is possible, although possibly somewhat slow. regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: ERROR: unrecognized node type

2021-09-29 Thread Tomas Vondra
ion (file:line) where the error is printed, and then set a breakpoint to that place. Makes it easier to generate the backtrace. regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: ERROR: unrecognized node type

2021-09-30 Thread Tomas Vondra
ause, but we can only speculate why and the query conditions look entirely reasonable. I suggest you do this: 1) start a session, identify the PID of the backend select pg_backend_pid(); 2) attach a debugger (e.g. gdb) to the pid gdb -p $PID 3) set breakpoint to the l

Re: create a new GIN index for my own type

2021-10-04 Thread Tomas Vondra
ID (gdb) c 3) run the CREATE INDEX query 4) get backtrace from the debugger (gdb) bt regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: Problem in pg_basebackup of 1.7 TB database while replicating in PostgreSQL 9.4.( Master and slave both are in postgreSQL 9.4)

2021-10-04 Thread Tomas Vondra
you looking for a faster / more efficient way to transfer the data? regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: create a new GIN index for my own type

2021-10-04 Thread Tomas Vondra
directly to the other person. regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: Avg/max size of these JSON docs in Postgres

2021-10-12 Thread Tomas Vondra
s an explicit 1GB limit per value, but having rows close to the 1GB limit is going to cause all sorts of unpredictable and rather painful issues :-( regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: GIN index

2021-10-13 Thread Tomas Vondra
probably ask them. 4) Don't post backtraces as screenshots. Copy them as text, attach them as a text file. 5) Continue in the thread you already started, otherwise it's impossible to follow the discussion. regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: Plans with bad estimates/paths

2021-11-16 Thread Tomas Vondra
ny joins as possible until the issue disappears. The simpler the query, the easier it is to investigate. And yes, replacing parts of a query with a temporary table is a common solution, because it's possible to collect statistics on it, build indexes etc. That usually solves estimation i

Re: Postgis - geography function

2022-01-05 Thread Tomas Vondra
//lists.osgeo.org/mailman/listinfo/postgis-users regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: Create and access a dictionary type

2022-01-05 Thread Tomas Vondra
On 1/5/22 14:17, Shaozhong SHI wrote: Any examples in Postgres to create a dictionary type to store and access key value pairs? I'd say JSONB can be used as an associative array, and e.g. in Python can map to dict data type. regards -- Tomas Vondra EnterpriseDB:

Re: Create and access a dictionary type

2022-01-05 Thread Tomas Vondra
On 1/5/22 17:24, Ron wrote: On 1/5/22 7:22 AM, Tomas Vondra wrote: On 1/5/22 14:17, Shaozhong SHI wrote: Any examples in Postgres to create a dictionary type to store and access key value pairs? I'd say JSONB can be used as an associative array, and e.g. in Python can map to dict

Re: Create and access a dictionary type

2022-01-05 Thread Tomas Vondra
r application to use what's available. regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: increasing effective_cache_size slows down join queries by a factor of 4000x

2022-02-02 Thread Tomas Vondra
data_pkey on data t (cost=0.57..21427806.53 rows=58785023 width=131) (actual time=0.024..0.482 rows=854 loops=1) Index Cond: (id > 205284974) It'd be interesting to see the plans without the LIMIT, as that makes the "actual" values low simply by terminating early.

Re: increasing effective_cache_size slows down join queries by a factor of 4000x

2022-02-04 Thread Tomas Vondra
plan look like? Is it using the merge sort of nested loop? I wonder if this might be formulated as a costing issue, pushing the planner to use the nested loop. [1] https://www.postgresql.org/message-id/flat/CAFQUnFhqkWuPCwQ1NmHYrisHJhYx4DoJak-dV%2BFcjyY6scooYA%40mail.gmail.com regards -- Toma

Re: increasing effective_cache_size slows down join queries by a factor of 4000x

2022-02-15 Thread Tomas Vondra
0.48 rows=1000 width=183) ... So it seems *more* expensive than the first plan. Taken to the extreme the planner could theoretically have chosen to use the first plan (and delay the condition until after the join). regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company

Re: query causes connection termination

2017-11-22 Thread Tomas Vondra
install debuginfo first, so that the backtrace makes sense. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: a question about oddities in the data directory

2017-11-27 Thread Tomas Vondra
de FROM pg_class WHERE relname = 'earlyprinttuples'; regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: large numbers of inserts out of memory strategy

2017-11-28 Thread Tomas Vondra
> migration utility to generate multiple files each with a limited > number of INSERTs to get around this issue but maybe there's > another/better way? > The question is what exactly runs out of memory, and how did you modify the configuration (particularly related to memory)

Re: large numbers of inserts out of memory strategy

2017-11-28 Thread Tomas Vondra
On 11/28/2017 06:54 PM, Ted Toth wrote: > On Tue, Nov 28, 2017 at 11:22 AM, Tomas Vondra > wrote: >> Hi, >> >> On 11/28/2017 06:17 PM, Ted Toth wrote: >>> I'm writing a migration utility to move data from non-rdbms data >>> source to a p

Re: large numbers of inserts out of memory strategy

2017-11-28 Thread Tomas Vondra
On 11/28/2017 07:26 PM, Ted Toth wrote: > On Tue, Nov 28, 2017 at 12:01 PM, Tomas Vondra > wrote: >> >> ... >> >> That is, most of the memory is allocated for SPI (2.4GB) and PL/pgSQL >> procedure (500MB). How do you do the load? What libraries/drivers? >

Re: Centos 6.9 and centos 7

2017-12-04 Thread Tomas Vondra
e policy? That typically affects short CPU-bound queries. Other than that, I recommend performing basic system benchmarks (CPU, memory, ...) and only if those machines perform equally should you look for issues in PostgreSQL. Chances are the root cause is in hw or OS, in which case yo

Re: Centos 6.9 and centos 7

2017-12-04 Thread Tomas Vondra
sed to know? Not only that depends on your internal deployment policies, but it's also much more a CentOS/RedHat question than PostgreSQL. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: Size of pg_multixact/members increases 11355

2017-12-13 Thread Tomas Vondra
it's unclear why the directory got so large. You could try setting autovacuum_multixact_freeze_max_age=0 and vacuuming the database, but it's hard to say if that will help. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: postgresql 9.5 has ocuuered OOM

2017-12-20 Thread Tomas Vondra
a single process, it might be a poor plan choice (e.g. hash aggregate may easily cause that). If all processes combined, then perhaps it's due to work_mem being too high. > what should I do to deal with this problem? > Hard to say, until you provide enough information. regards -- Tom

Re: Hardware advice

2018-01-23 Thread Tomas Vondra
ither find out what your actual needs are (by looking at the current system and extrapolating it in some way) and sizing the hardware accordingly. Or you can squeeze as much money from the management as possible, and buying the shiniest stuff out possible. > Oh yeah, apparently we're ma

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