Re: recovering from "found xmin ... from before relfrozenxid ..."

On Wed, 19 Aug 2020 at 20:45, Ashutosh Sharma wrote: > > On Wed, Aug 19, 2020 at 3:55 PM Masahiko Sawada > wrote: > > > > On Wed, 19 Aug 2020 at 15:09, Ashutosh Sharma wrote: > > > > > > On Wed, Aug 19, 2020 at 9:27 AM Masahiko Sawada > > > wrote: > > > > > > > > On Mon, 17 Aug 2020 at 15:05,

Re: "ccold" left by reindex concurrently are droppable?

On Wed, Aug 19, 2020 at 05:13:12PM -0400, Alvaro Herrera wrote: > In other words I propose to reword this paragraph as follows: > >If the transient index created during the concurrent operation is >suffixed ccnew, the recommended recovery method >is to drop the invalid index using

Re: display offset along with block number in vacuum errors

On Wed, Aug 19, 2020 at 12:54 PM Masahiko Sawada wrote: > > On Tue, 18 Aug 2020 at 13:06, Amit Kapila wrote: > > > > > > I don't think we need to expose LVRelStats. We can just pass the > > address of vacrelstats->offset_num to achieve what we want. I have > > tried that and it works, see the >

Re: Include access method in listTables output

On Mon, Aug 17, 2020 at 11:10:05PM +0530, vignesh C wrote: > On Sat, Aug 1, 2020 at 8:12 AM vignesh C wrote: > > > > > > > > +-- access method column should not be displayed for sequences > > > > +\ds+ > > > > > > > > - List of relations > > > > > > > > > > > > - Schema

Re: Asynchronous Append on postgres_fdw nodes.

On Thu, Jul 02, 2020 at 11:14:48AM +0900, Kyotaro Horiguchi wrote: > As the result of a discussion with Fujita-san off-list, I'm going to > hold off development until he decides whether mine or Thomas' is > better. The latest patch doesn't apply so I set as WoA.

Re: [PG13] Planning (time + buffers) data structure in explain plan (format text)

On Thu, 20 Aug 2020 at 03:31, Fujii Masao wrote: > With the patch, for example, whatever "summary" settng is, "buffers on" > displays the planner's buffer usage if it happens. I forgot to mention earlier, you'll also need to remove the part in the docs that mentions BUFFERS requires ANALYZE.

Re: Hybrid Hash/Nested Loop joins and caching results from subplans

čt 20. 8. 2020 v 0:04 odesílatel David Rowley napsal: > On Wed, 19 Aug 2020 at 16:18, Pavel Stehule > wrote: > > > > > > > > st 19. 8. 2020 v 5:48 odesílatel David Rowley > napsal: > >> Current method: > >> > >> regression=# explain (analyze, costs off, timing off, summary off) > >> select

Re: SyncRepLock acquired exclusively in default configuration

At Wed, 19 Aug 2020 21:41:03 +0900, Fujii Masao wrote in > > > On 2020/08/12 15:32, Masahiko Sawada wrote: > > On Wed, 12 Aug 2020 at 14:06, Asim Praveen wrote: > >> > >> > >> > >>> On 11-Aug-2020, at 8:57 PM, Robert Haas wrote: > >>> > >>> I think this gets to the root of the issue. If we

Re: Creating a function for exposing memory usage of backend process

On 2020/08/20 0:01, Tom Lane wrote: > The only situation I could imagine where this would have any use is > where there is long-term (cross-query) bloat in, say, CacheMemoryContext Yeah, in cases where a very large number of sessions are connected to the DB for very long periods of time, the

The number of logical replication slot or wal sender recommend

Hello I have a publisher instance, cpu 32 core, ram 64GB, with SSD and installed PostgreSQL 10 on it. I want to use logical replication with it , I create publication on it, add about 20 tables in the pub, each tables will have about 1 million line data,. I wonder how many subscriber

Re: SyncRepLock acquired exclusively in default configuration

At Wed, 19 Aug 2020 13:20:46 +, Asim Praveen wrote in > > > > On 12-Aug-2020, at 12:02 PM, Masahiko Sawada > > wrote: > > > > On Wed, 12 Aug 2020 at 14:06, Asim Praveen wrote: > >> > >> > >> > >>> On 11-Aug-2020, at 8:57 PM, Robert Haas wrote: > >>> > >>> I think this gets to the

Re: Creating a function for exposing memory usage of backend process

On 2020/08/20 10:43, Andres Freund wrote: Hi, On 2020-08-19 21:29:06 -0400, Tom Lane wrote: Andres Freund writes: On 2020-08-19 11:01:37 -0400, Tom Lane wrote: I agree with that, but I think this patch has a bigger problem: why bother at all? It seems like a waste of code space and

Re: Creating a function for exposing memory usage of backend process

On 2020/08/20 0:01, Tom Lane wrote: Hadn't been paying attention to this thread up till now, but ... Michael Paquier writes: By the way, I was looking at the code that has been committed, and I think that it is awkward to have a SQL function in mcxt.c, which is a rather low-level

Re: Creating foreign key on partitioned table is too slow

Hi, On Thu, Aug 20, 2020 at 3:06 AM Alvaro Herrera wrote: > On 2020-Aug-19, Amit Langote wrote: > > On Thu, Aug 6, 2020 at 4:25 PM kato-...@fujitsu.com > > wrote: > > > On Wednesday, August 5, 2020 9:43 AM I wrote: > > > > I'll report the result before the end of August . > > > > > > I test

Re: Creating a function for exposing memory usage of backend process

Hi, On 2020-08-19 21:29:06 -0400, Tom Lane wrote: > Andres Freund writes: > > On 2020-08-19 11:01:37 -0400, Tom Lane wrote: > >> I agree with that, but I think this patch has a bigger problem: > >> why bother at all? It seems like a waste of code space and future > >> maintenance effort,

Re: Creating a function for exposing memory usage of backend process

Andres Freund writes: > On 2020-08-19 11:01:37 -0400, Tom Lane wrote: >> I agree with that, but I think this patch has a bigger problem: >> why bother at all? It seems like a waste of code space and future >> maintenance effort, because there is no use-case. > I don't agree with this at all. I

RE: Implement UNLOGGED clause for COPY FROM

Hello. Apologies for the delay. > > When the server crash occurs during data loading of COPY UNLOGGED, > > it's a must to keep index consistent of course. > > I'm thinking that to rebuild the indexes on the target table would work. > > > > In my opinion, UNLOGGED clause must be designed to

Re: Hybrid Hash/Nested Loop joins and caching results from subplans

On Thu, 20 Aug 2020 at 10:58, Alvaro Herrera wrote: > On the performance aspect, I wonder what the overhead is, particularly > considering Tom's point of making these nodes more expensive for cases > with no caching. It's likely small. I've not written any code but only thought about it and I

Re: [PG13] Planning (time + buffers) data structure in explain plan (format text)

On Thu, 20 Aug 2020 at 03:31, Fujii Masao wrote: > > > > On 2020/08/19 19:39, David Rowley wrote: > > On Wed, 19 Aug 2020 at 21:05, Julien Rouhaud wrote: > >> > >> On Wed, Aug 19, 2020 at 08:49:48PM +1200, David Rowley wrote: > >>> However, I'm not quite sure how we should handle if someone

Re: Optimising compactify_tuples()

On Wed, Aug 19, 2020 at 11:41 PM Thomas Munro wrote: > On Tue, Aug 18, 2020 at 6:53 AM Peter Geoghegan wrote: > > I definitely think that we should have something like this, though. > > It's a relatively easy win. There are plenty of workloads that spend > > lots of time on pruning. > > Alright

Re: Hybrid Hash/Nested Loop joins and caching results from subplans

On 2020-Aug-19, David Rowley wrote: > Andres' suggestion: > > regression=# explain (analyze, costs off, timing off, summary off) > select count(*) from tenk1 t1 inner join tenk1 t2 on > t1.twenty=t2.unique1; > QUERY PLAN >

Re: Creating a function for exposing memory usage of backend process

Hi, On 2020-08-19 11:01:37 -0400, Tom Lane wrote: > Hadn't been paying attention to this thread up till now, but ... > > Michael Paquier writes: > > By the way, I was looking at the code that has been committed, and I > > think that it is awkward to have a SQL function in mcxt.c, which is a > >

Re: Hybrid Hash/Nested Loop joins and caching results from subplans

On Wed, 19 Aug 2020 at 16:18, Pavel Stehule wrote: > > > > st 19. 8. 2020 v 5:48 odesílatel David Rowley napsal: >> Current method: >> >> regression=# explain (analyze, costs off, timing off, summary off) >> select twenty, (select count(*) from tenk1 t2 where t1.twenty = >> t2.twenty) from tenk1

Re: Hybrid Hash/Nested Loop joins and caching results from subplans

On Wed, 19 Aug 2020 at 16:23, Tom Lane wrote: > > David Rowley writes: > > I don't object to making the change. I just object to making it only > > to put it back again later when someone else speaks up that they'd > > prefer to keep nodes modular and not overload them in obscure ways. > > > So

"ccold" left by reindex concurrently are droppable?

Hello The REINDEX CONCURRENTLY documentation states that if a transient index used lingers, the fix is to drop the invalid index and perform RC again; and that this is to be done for "ccnew" indexes and also for "ccold" indexes: The recommended recovery method in such cases is to drop the

Re: Problem with accessing TOAST data in stored procedures

st 19. 8. 2020 v 20:59 odesílatel Konstantin Knizhnik < k.knizh...@postgrespro.ru> napsal: > > > On 19.08.2020 21:50, Pavel Stehule wrote: > > Hi > > st 19. 8. 2020 v 19:22 odesílatel Konstantin Knizhnik < > k.knizh...@postgrespro.ru> napsal: > >> Hi hackers, >> >> More than month ago I have sent

Re: Problem with accessing TOAST data in stored procedures

On 19.08.2020 21:50, Pavel Stehule wrote: Hi st 19. 8. 2020 v 19:22 odesílatel Konstantin Knizhnik mailto:k.knizh...@postgrespro.ru>> napsal: Hi hackers, More than month ago I have sent bug report to pgsql-bugs:

Re: Problem with accessing TOAST data in stored procedures

Hi st 19. 8. 2020 v 19:22 odesílatel Konstantin Knizhnik < k.knizh...@postgrespro.ru> napsal: > Hi hackers, > > More than month ago I have sent bug report to pgsql-bugs: > > > https://www.postgresql.org/message-id/flat/5d335911-fb25-60cd-4aa7-a5bd0954aea0%40postgrespro.ru > > with the proposed

Re: remove spurious CREATE INDEX CONCURRENTLY wait

On 2020-Aug-11, James Coleman wrote: > In [3] I'd brought up that a function index can do arbitrary > operations (including, terribly, a query of another table), and Andres > (in [4]) noted that: > > > Well, even if we consider this an actual problem, we could still use > > PROC_IN_CIC for

Re: Creating foreign key on partitioned table is too slow

On 2020-Aug-19, Amit Langote wrote: Hello > On Thu, Aug 6, 2020 at 4:25 PM kato-...@fujitsu.com > wrote: > > On Wednesday, August 5, 2020 9:43 AM I wrote: > > > I'll report the result before the end of August . > > > > I test v2-0001-build-partdesc-memcxt.patch at 9a9db08ae4 and it is ok. > >

Re: deb repo doesn't have latest. or possible to update web page?

On Wed, Aug 19, 2020 at 7:04 PM Roger Pack wrote: > As a note I tried to use the deb repo today: > > https://www.postgresql.org/download/linux/debian/ > > with an old box on Wheezy. > It only seems to have binaries up to postgres 10. > > Might be nice to make a note on the web page so people

Problem with accessing TOAST data in stored procedures

Hi hackers, More than month ago I have sent bug report to pgsql-bugs: https://www.postgresql.org/message-id/flat/5d335911-fb25-60cd-4aa7-a5bd0954aea0%40postgrespro.ru with the proposed patch but have not received any response. I wonder if there is some other way to fix this issue and does

deb repo doesn't have latest. or possible to update web page?

As a note I tried to use the deb repo today: https://www.postgresql.org/download/linux/debian/ with an old box on Wheezy. It only seems to have binaries up to postgres 10. Might be nice to make a note on the web page so people realize some distro's aren't supported fully instead of (if they're

Re: stress test for parallel workers

Thomas Munro writes: > On Tue, Jul 28, 2020 at 3:27 PM Tom Lane wrote: >> Anyway, I guess the interesting question for us is how long it >> will take for this fix to propagate into real-world systems. >> I don't have much of a clue about the Linux kernel workflow, >> anybody want to venture a

Re: [PG13] Planning (time + buffers) data structure in explain plan (format text)

On 2020/08/19 19:39, David Rowley wrote: On Wed, 19 Aug 2020 at 21:05, Julien Rouhaud wrote: On Wed, Aug 19, 2020 at 08:49:48PM +1200, David Rowley wrote: However, I'm not quite sure how we should handle if someone does: EXPLAIN (BUFFERS on, SUMMARY off). Without the summary, there's no

Re: Performing partition pruning using row value

The following review has been posted through the commitfest application: make installcheck-world: tested, passed Implements feature: tested, passed Spec compliant: tested, passed Documentation:not tested I have performed testing of the patch with row comparison

Re: Creating a function for exposing memory usage of backend process

Hadn't been paying attention to this thread up till now, but ... Michael Paquier writes: > By the way, I was looking at the code that has been committed, and I > think that it is awkward to have a SQL function in mcxt.c, which is a > rather low-level interface. I think that this new code should

Re: Feature improvement: can we add queryId for pg_catalog.pg_stat_activity view?

On Tue, Jul 28, 2020 at 10:55:04AM +0200, Julien Rouhaud wrote: > On Tue, Jul 28, 2020 at 10:07 AM torikoshia > wrote: > > > > Thanks for updating! > > I tested the patch setting log_statement = 'all', but %Q in > > log_line_prefix > > was always 0 even when pg_stat_statements.queryid and > >

Re: Creating a function for exposing memory usage of backend process

On Wed, Aug 19, 2020 at 06:12:02PM +0900, Fujii Masao wrote: > On 2020/08/19 17:40, torikoshia wrote: >> Yes, I didn't add regression tests because of the unstability of the output. >> I thought it would be OK since other views like pg_stat_slru and >> pg_shmem_allocations >> didn't have tests

Re: prepared transaction isolation tests

On 8/18/20 9:22 PM, Andres Freund wrote: > Hi, > > This thread started on committers, at > https://www.postgresql.org/message-id/20200818234532.uiafo5br5lo6zhya%40alap3.anarazel.de > > In it I wanted to add a isolation test around prepared transactions: > > On 2020-08-18 16:45:32 -0700, Andres

Re: prepared transaction isolation tests

On Tue, Aug 18, 2020 at 07:34:00PM -0700, Andres Freund wrote: > It seems like the buildfarm ought to configure the started server with a > bunch of prepared transactions, in that case? At least going forward? Agreed. Testing with max_prepared_transactions > 0 has much more value than not, for

Re: Print logical WAL message content

Thanks Alvaro for review. On Wed, Aug 19, 2020 at 3:21 AM Alvaro Herrera wrote: > > I didn't like that you're documenting the message format in the new > function: > > > xl_logical_message *xlrec = (xl_logical_message *) rec; > > + /* > > + * Per

Re: More tests with USING INDEX replident and dropped indexes

On Wed, Aug 19, 2020 at 05:33:36PM +0530, Rahila Syed wrote: > I couldn't test the patch as it does not apply cleanly on master. The CF bot is green, and I can apply v2 cleanly FWIW: http://commitfest.cputube.org/michael-paquier.html > Please find below some review comments: > > 1. Would it

Re: SyncRepLock acquired exclusively in default configuration

> On 12-Aug-2020, at 12:02 PM, Masahiko Sawada > wrote: > > On Wed, 12 Aug 2020 at 14:06, Asim Praveen wrote: >> >> >> >>> On 11-Aug-2020, at 8:57 PM, Robert Haas wrote: >>> >>> I think this gets to the root of the issue. If we check the flag >>> without a lock, we might see a slightly

Re: COPY FREEZE and setting PD_ALL_VISIBLE/visibility map bits

On 18.08.2020 02:54, Alvaro Herrera wrote: On 2020-Aug-14, Ibrar Ahmed wrote: The table used for the test contains three columns (integer, text, varchar). The total number of rows is 1000 in total. Unpatched (Master: 92c12e46d5f1e25fc85608a6d6a19b8f5ea02600) COPY: 9069.432 ms vacuum;

Refactor pg_rewind code and make it work against a standby

Hi, I started to hack on making pg_rewind crash-safe (see [1]), but I quickly got side-tracked into refactoring and tidying up up the code in general. I ended up with this series of patches: The first four patches are just refactoring that make the code and the logic more readable. Tom Lane

Re: track_planning causing performance regression

The following review has been posted through the commitfest application: make installcheck-world: tested, passed Implements feature: not tested Spec compliant: not tested Documentation:not tested Overall, the patch works fine. However, I have a few observations: (1)

Re: SyncRepLock acquired exclusively in default configuration

On 2020/08/12 15:32, Masahiko Sawada wrote: On Wed, 12 Aug 2020 at 14:06, Asim Praveen wrote: On 11-Aug-2020, at 8:57 PM, Robert Haas wrote: I think this gets to the root of the issue. If we check the flag without a lock, we might see a slightly stale value. But, considering that

Re: More tests with USING INDEX replident and dropped indexes

Hi, I couldn't test the patch as it does not apply cleanly on master. Please find below some review comments: 1. Would it better to throw a warning at the time of dropping the REPLICA IDENTITY index that it would also  drop the REPLICA IDENTITY of the parent table? 2. CCI is used after

Re: recovering from "found xmin ... from before relfrozenxid ..."

On Wed, Aug 19, 2020 at 3:55 PM Masahiko Sawada wrote: > > On Wed, 19 Aug 2020 at 15:09, Ashutosh Sharma wrote: > > > > On Wed, Aug 19, 2020 at 9:27 AM Masahiko Sawada > > wrote: > > > > > > On Mon, 17 Aug 2020 at 15:05, Ashutosh Sharma > > > wrote: > > > > > > > > > pg_force_freeze() can

Re: Optimising compactify_tuples()

On Tue, Aug 18, 2020 at 6:53 AM Peter Geoghegan wrote: > I definitely think that we should have something like this, though. > It's a relatively easy win. There are plenty of workloads that spend > lots of time on pruning. Alright then, here's an attempt to flesh the idea out a bit more, and

Re: [PG13] Planning (time + buffers) data structure in explain plan (format text)

On Wed, 19 Aug 2020 at 22:39, David Rowley wrote: > so, maybe we can just error if analyze == off AND buffers == on AND > summary == off. We likely should pay attention to analyze there as it > seems perfectly fine to EXPLAIN (ANALYZE, BUFFERS, SUMMARY off). We > quite often do SUMMARY off for

Re: [PG13] Planning (time + buffers) data structure in explain plan (format text)

On Wed, 19 Aug 2020 at 21:05, Julien Rouhaud wrote: > > On Wed, Aug 19, 2020 at 08:49:48PM +1200, David Rowley wrote: > > However, I'm not quite sure how we should handle if someone does: > > EXPLAIN (BUFFERS on, SUMMARY off). Without the summary, there's no > > place to print the buffers, which

Re: recovering from "found xmin ... from before relfrozenxid ..."

On Wed, 19 Aug 2020 at 15:09, Ashutosh Sharma wrote: > > On Wed, Aug 19, 2020 at 9:27 AM Masahiko Sawada > wrote: > > > > On Mon, 17 Aug 2020 at 15:05, Ashutosh Sharma wrote: > > > > > > > pg_force_freeze() can revival a tuple that is already deleted but not > > > > vacuumed yet. Therefore, the

Re: Creating a function for exposing memory usage of backend process

On 2020/08/19 17:40, torikoshia wrote: On 2020-08-19 15:48, Fujii Masao wrote: On 2020/08/19 9:43, torikoshia wrote: On 2020-08-18 22:54, Fujii Masao wrote: On 2020/08/18 18:41, torikoshia wrote: On 2020-08-17 21:19, Fujii Masao wrote: On 2020/08/17 21:14, Fujii Masao wrote: On

Re: [PG13] Planning (time + buffers) data structure in explain plan (format text)

On Wed, Aug 19, 2020 at 08:49:48PM +1200, David Rowley wrote: > On Wed, 19 Aug 2020 at 19:22, Julien Rouhaud wrote: > > Hearing no objection, here's a patch to change the output as suggested by > > Pierre: > > > > =# explain (analyze, buffers) select * from pg_class; > >

Re: [PG13] Planning (time + buffers) data structure in explain plan (format text)

On Wed, 19 Aug 2020 at 19:22, Julien Rouhaud wrote: > Hearing no objection, here's a patch to change the output as suggested by > Pierre: > > =# explain (analyze, buffers) select * from pg_class; >QUERY PLAN >

Re: Creating a function for exposing memory usage of backend process

On 2020-08-19 15:48, Fujii Masao wrote: On 2020/08/19 9:43, torikoshia wrote: On 2020-08-18 22:54, Fujii Masao wrote: On 2020/08/18 18:41, torikoshia wrote: On 2020-08-17 21:19, Fujii Masao wrote: On 2020/08/17 21:14, Fujii Masao wrote: On 2020-08-07 16:38, Kasahara Tatsuhito wrote: The

Re: [PATCH] - Provide robust alternatives for replace_string

‐‐‐ Original Message ‐‐‐ On Friday, 7 August 2020 09:02, Asim Praveen wrote: > > On 05-Aug-2020, at 7:01 PM, Alvaro Herrera alvhe...@2ndquadrant.com wrote: > > On 2020-Aug-05, Asim Praveen wrote: > > > > > Please find attached a StringInfo based solution to this problem. It > > > uses

Re: PATCH: logical_work_mem and logical streaming of large in-progress transactions

On Wed, Aug 19, 2020 at 12:20 PM Amit Kapila wrote: > > On Wed, Aug 19, 2020 at 10:10 AM Amit Kapila wrote: > > > > On Mon, Aug 17, 2020 at 6:29 PM Dilip Kumar wrote: > > > > > > > > > In last patch v49-0001, there is one issue, Basically, I have called > > > BufFileFlush in all the cases.

Re: PATCH: logical_work_mem and logical streaming of large in-progress transactions

On Wed, Aug 19, 2020 at 10:11 AM Amit Kapila wrote: > > On Mon, Aug 17, 2020 at 6:29 PM Dilip Kumar wrote: > > > > > > In last patch v49-0001, there is one issue, Basically, I have called > > BufFileFlush in all the cases. But, ideally, we can not call this if > > the underlying files are

Re: display offset along with block number in vacuum errors

On Tue, 18 Aug 2020 at 13:06, Amit Kapila wrote: > > On Mon, Aug 17, 2020 at 11:38 AM Masahiko Sawada > wrote: > > > > On Sat, 15 Aug 2020 at 12:19, Amit Kapila wrote: > > > > > > The reason why I have not included heap_page_prune related change in > > > the patch is that I don't want to

Re: [PG13] Planning (time + buffers) data structure in explain plan (format text)

On Tue, Aug 18, 2020 at 10:27:06PM -0500, Justin Pryzby wrote: > On Fri, Aug 07, 2020 at 02:30:01PM +0200, Pierre Giraud wrote: > > Hi all, > > > > As far as I understand, in the upcoming version 13, information about > > buffers used during planning is now available in the explain plan. > > > >

Re: Binary search in ScalarArrayOpExpr for OR'd constant arrays

On 01/05/2020 05:20, James Coleman wrote: On Tue, Apr 28, 2020 at 8:25 AM Tomas Vondra wrote: ... Any particular reasons to pick dynahash over simplehash? ISTM we're using simplehash elsewhere in the executor (grouping, tidbitmap, ...), while there are not many places using dynahash for simple

Re: PATCH: logical_work_mem and logical streaming of large in-progress transactions

On Wed, Aug 19, 2020 at 10:10 AM Amit Kapila wrote: > > On Mon, Aug 17, 2020 at 6:29 PM Dilip Kumar wrote: > > > > > > In last patch v49-0001, there is one issue, Basically, I have called > > BufFileFlush in all the cases. But, ideally, we can not call this if > > the underlying files are

Re: Creating a function for exposing memory usage of backend process

On 2020/08/19 9:43, torikoshia wrote: On 2020-08-18 22:54, Fujii Masao wrote: On 2020/08/18 18:41, torikoshia wrote: On 2020-08-17 21:19, Fujii Masao wrote: On 2020/08/17 21:14, Fujii Masao wrote: On 2020-08-07 16:38, Kasahara Tatsuhito wrote: The following review has been posted through

Re: recovering from "found xmin ... from before relfrozenxid ..."

On Wed, Aug 19, 2020 at 9:27 AM Masahiko Sawada wrote: > > On Mon, 17 Aug 2020 at 15:05, Ashutosh Sharma wrote: > > > > > pg_force_freeze() can revival a tuple that is already deleted but not > > > vacuumed yet. Therefore, the user might need to reindex indexes after > > > using that function.