Re: [HACKERS] Hash index creation warning

2015-08-05 Thread Bruce Momjian
On Fri, Jun 26, 2015 at 11:40:27AM -0400, Robert Haas wrote:
> On Wed, Jun 24, 2015 at 4:53 AM, Peter Geoghegan  wrote:
> > On Wed, Jun 24, 2015 at 1:45 AM, Craig Ringer  wrote:
> >> WARNING: hash indexes are not crash-safe, not replicated, and their
> >> use is discouraged
> >
> > +1
> 
> I'm not wild about this rewording; I think that if users don't know
> what WAL is, they probably need to know that in order to make good
> decisions about whether to use hash indexes.  But I don't feel
> super-strongly about it.

Coming late to this, but I think Robert is right.  WAL is used for crash
recovery, PITR, and streaming replication, and I am not sure we want to
specify all of those in the warning message.

-- 
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  EnterpriseDB http://enterprisedb.com

  + Everyone has their own god. +


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Re: [HACKERS] Hash index creation warning

2015-06-26 Thread Robert Haas
On Wed, Jun 24, 2015 at 4:53 AM, Peter Geoghegan  wrote:
> On Wed, Jun 24, 2015 at 1:45 AM, Craig Ringer  wrote:
>> WARNING: hash indexes are not crash-safe, not replicated, and their
>> use is discouraged
>
> +1

I'm not wild about this rewording; I think that if users don't know
what WAL is, they probably need to know that in order to make good
decisions about whether to use hash indexes.  But I don't feel
super-strongly about it.

-- 
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Re: [HACKERS] Hash index creation warning

2015-06-26 Thread Robert Haas
On Wed, Jun 24, 2015 at 3:06 AM, Michael Paquier
 wrote:
> On Wed, Jun 24, 2015 at 12:27 AM, Robert Haas wrote:
>> I think you should be testing RelationNeedsWAL(), not the
>> relpersistence directly.  The same point applies for temporary
>> indexes.
>
> Indeed. Patch updated attached.

Committed.

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Re: [HACKERS] Hash index creation warning

2015-06-24 Thread Peter Geoghegan
On Wed, Jun 24, 2015 at 1:45 AM, Craig Ringer  wrote:
> WARNING: hash indexes are not crash-safe, not replicated, and their
> use is discouraged

+1


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Re: [HACKERS] Hash index creation warning

2015-06-24 Thread Craig Ringer
On 18 October 2014 at 02:36, Bruce Momjian  wrote:
> On Fri, Oct 17, 2014 at 12:56:52PM -0400, Tom Lane wrote:
>> David G Johnston  writes:
>> > The question is whether we explain the implications of not being WAL-logged
>> > in an error message or simply state the fact and let the documentation
>> > explain the hazards - basically just output:
>> > "hash indexes are not WAL-logged and their use is discouraged"
>>
>> +1.  The warning message is not the place to be trying to explain all the
>> details.

While I don't think it should explain all the details, "WAL-logged"
will mean *nothing* to most users, including most of those who're
using streaming replication, PITR, etc.

I would strongly prefer to see something that conveys some meaning to
a user who doesn't know PostgreSQL's innards, since by the time "WAL
logged" means much to you, you've got a good chance of having already
learned that hash indexes aren't crash-safe. Or of reading the manual.

Perhaps:

WARNING: hash indexes are not crash-safe, not replicated, and their
use is discouraged

?

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Re: [HACKERS] Hash index creation warning

2015-06-24 Thread Michael Paquier
On Wed, Jun 24, 2015 at 12:27 AM, Robert Haas wrote:
> I think you should be testing RelationNeedsWAL(), not the
> relpersistence directly.  The same point applies for temporary
> indexes.

Indeed. Patch updated attached.
-- 
Michael
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 7340a1f..b450bcf 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -490,7 +490,8 @@ DefineIndex(Oid relationId,
 	accessMethodId = HeapTupleGetOid(tuple);
 	accessMethodForm = (Form_pg_am) GETSTRUCT(tuple);
 
-	if (strcmp(accessMethodName, "hash") == 0)
+	if (strcmp(accessMethodName, "hash") == 0 &&
+		RelationNeedsWAL(rel))
 		ereport(WARNING,
 (errmsg("hash indexes are not WAL-logged and their use is discouraged")));
 
diff --git a/src/test/regress/expected/create_index.out b/src/test/regress/expected/create_index.out
index 5c2e67d..b72e65d 100644
--- a/src/test/regress/expected/create_index.out
+++ b/src/test/regress/expected/create_index.out
@@ -2342,6 +2342,9 @@ CREATE INDEX hash_txt_index ON hash_txt_heap USING hash (random text_ops);
 WARNING:  hash indexes are not WAL-logged and their use is discouraged
 CREATE INDEX hash_f8_index ON hash_f8_heap USING hash (random float8_ops);
 WARNING:  hash indexes are not WAL-logged and their use is discouraged
+CREATE UNLOGGED TABLE unlogged_hash_table (id int4);
+CREATE INDEX unlogged_hash_index ON unlogged_hash_table USING hash (id int4_ops);
+DROP TABLE unlogged_hash_table;
 -- CREATE INDEX hash_ovfl_index ON hash_ovfl_heap USING hash (x int4_ops);
 --
 -- Test functional index
diff --git a/src/test/regress/sql/create_index.sql b/src/test/regress/sql/create_index.sql
index 67dd2f0..ff86953 100644
--- a/src/test/regress/sql/create_index.sql
+++ b/src/test/regress/sql/create_index.sql
@@ -684,6 +684,10 @@ CREATE INDEX hash_txt_index ON hash_txt_heap USING hash (random text_ops);
 
 CREATE INDEX hash_f8_index ON hash_f8_heap USING hash (random float8_ops);
 
+CREATE UNLOGGED TABLE unlogged_hash_table (id int4);
+CREATE INDEX unlogged_hash_index ON unlogged_hash_table USING hash (id int4_ops);
+DROP TABLE unlogged_hash_table;
+
 -- CREATE INDEX hash_ovfl_index ON hash_ovfl_heap USING hash (x int4_ops);
 
 

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Re: [HACKERS] Hash index creation warning

2015-06-23 Thread Robert Haas
On Mon, Jun 22, 2015 at 8:46 PM, Michael Paquier
 wrote:
> On Tue, Jun 23, 2015 at 9:06 AM, Jim Nasby  wrote:
>> On 6/12/15 5:00 PM, Thom Brown wrote:
>>>
>>> On 18 October 2014 at 15:36, Bruce Momjian  wrote:

 On Fri, Oct 17, 2014 at 02:36:55PM -0400, Bruce Momjian wrote:
>
> On Fri, Oct 17, 2014 at 12:56:52PM -0400, Tom Lane wrote:
>>
>> David G Johnston  writes:
>>>
>>> The question is whether we explain the implications of not being
>>> WAL-logged
>>> in an error message or simply state the fact and let the documentation
>>> explain the hazards - basically just output:
>>> "hash indexes are not WAL-logged and their use is discouraged"
>>
>>
>> +1.  The warning message is not the place to be trying to explain all
>> the
>> details.
>
>
> OK, updated patch attached.


 Patch applied.
>>>
>>>
>>> I only just noticed this item when I read the release notes.  Should
>>> we bother warning when used on an unlogged table?
>>
>>
>> Not really; but I think the bigger question at this point is if we want to
>> change it this late in the game.
>
> Changing it even during beta looks acceptable to me. I think that it
> is mainly a matter to have a patch (here is one), and someone to push
> it as everybody here seem to agree that for UNLOGGED tables this
> warning has little sense.

I think you should be testing RelationNeedsWAL(), not the
relpersistence directly.  The same point applies for temporary
indexes.

-- 
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Re: [HACKERS] Hash index creation warning

2015-06-22 Thread Michael Paquier
On Tue, Jun 23, 2015 at 9:06 AM, Jim Nasby  wrote:
> On 6/12/15 5:00 PM, Thom Brown wrote:
>>
>> On 18 October 2014 at 15:36, Bruce Momjian  wrote:
>>>
>>> On Fri, Oct 17, 2014 at 02:36:55PM -0400, Bruce Momjian wrote:

 On Fri, Oct 17, 2014 at 12:56:52PM -0400, Tom Lane wrote:
>
> David G Johnston  writes:
>>
>> The question is whether we explain the implications of not being
>> WAL-logged
>> in an error message or simply state the fact and let the documentation
>> explain the hazards - basically just output:
>> "hash indexes are not WAL-logged and their use is discouraged"
>
>
> +1.  The warning message is not the place to be trying to explain all
> the
> details.


 OK, updated patch attached.
>>>
>>>
>>> Patch applied.
>>
>>
>> I only just noticed this item when I read the release notes.  Should
>> we bother warning when used on an unlogged table?
>
>
> Not really; but I think the bigger question at this point is if we want to
> change it this late in the game.

Changing it even during beta looks acceptable to me. I think that it
is mainly a matter to have a patch (here is one), and someone to push
it as everybody here seem to agree that for UNLOGGED tables this
warning has little sense.
-- 
Michael
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 7340a1f..49ad9d6 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -490,7 +490,8 @@ DefineIndex(Oid relationId,
 	accessMethodId = HeapTupleGetOid(tuple);
 	accessMethodForm = (Form_pg_am) GETSTRUCT(tuple);
 
-	if (strcmp(accessMethodName, "hash") == 0)
+	if (strcmp(accessMethodName, "hash") == 0 &&
+		rel->rd_rel->relpersistence != RELPERSISTENCE_UNLOGGED)
 		ereport(WARNING,
 (errmsg("hash indexes are not WAL-logged and their use is discouraged")));
 
diff --git a/src/test/regress/expected/create_index.out b/src/test/regress/expected/create_index.out
index 5c2e67d..b72e65d 100644
--- a/src/test/regress/expected/create_index.out
+++ b/src/test/regress/expected/create_index.out
@@ -2342,6 +2342,9 @@ CREATE INDEX hash_txt_index ON hash_txt_heap USING hash (random text_ops);
 WARNING:  hash indexes are not WAL-logged and their use is discouraged
 CREATE INDEX hash_f8_index ON hash_f8_heap USING hash (random float8_ops);
 WARNING:  hash indexes are not WAL-logged and their use is discouraged
+CREATE UNLOGGED TABLE unlogged_hash_table (id int4);
+CREATE INDEX unlogged_hash_index ON unlogged_hash_table USING hash (id int4_ops);
+DROP TABLE unlogged_hash_table;
 -- CREATE INDEX hash_ovfl_index ON hash_ovfl_heap USING hash (x int4_ops);
 --
 -- Test functional index
diff --git a/src/test/regress/sql/create_index.sql b/src/test/regress/sql/create_index.sql
index 67dd2f0..ff86953 100644
--- a/src/test/regress/sql/create_index.sql
+++ b/src/test/regress/sql/create_index.sql
@@ -684,6 +684,10 @@ CREATE INDEX hash_txt_index ON hash_txt_heap USING hash (random text_ops);
 
 CREATE INDEX hash_f8_index ON hash_f8_heap USING hash (random float8_ops);
 
+CREATE UNLOGGED TABLE unlogged_hash_table (id int4);
+CREATE INDEX unlogged_hash_index ON unlogged_hash_table USING hash (id int4_ops);
+DROP TABLE unlogged_hash_table;
+
 -- CREATE INDEX hash_ovfl_index ON hash_ovfl_heap USING hash (x int4_ops);
 
 

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Re: [HACKERS] Hash index creation warning

2015-06-22 Thread Jim Nasby

On 6/12/15 5:00 PM, Thom Brown wrote:

On 18 October 2014 at 15:36, Bruce Momjian  wrote:

On Fri, Oct 17, 2014 at 02:36:55PM -0400, Bruce Momjian wrote:

On Fri, Oct 17, 2014 at 12:56:52PM -0400, Tom Lane wrote:

David G Johnston  writes:

The question is whether we explain the implications of not being WAL-logged
in an error message or simply state the fact and let the documentation
explain the hazards - basically just output:
"hash indexes are not WAL-logged and their use is discouraged"


+1.  The warning message is not the place to be trying to explain all the
details.


OK, updated patch attached.


Patch applied.


I only just noticed this item when I read the release notes.  Should
we bother warning when used on an unlogged table?


Not really; but I think the bigger question at this point is if we want 
to change it this late in the game.

--
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Data in Trouble? Get it in Treble! http://BlueTreble.com


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Re: [HACKERS] Hash index creation warning

2015-06-12 Thread Thom Brown
On 18 October 2014 at 15:36, Bruce Momjian  wrote:
> On Fri, Oct 17, 2014 at 02:36:55PM -0400, Bruce Momjian wrote:
>> On Fri, Oct 17, 2014 at 12:56:52PM -0400, Tom Lane wrote:
>> > David G Johnston  writes:
>> > > The question is whether we explain the implications of not being 
>> > > WAL-logged
>> > > in an error message or simply state the fact and let the documentation
>> > > explain the hazards - basically just output:
>> > > "hash indexes are not WAL-logged and their use is discouraged"
>> >
>> > +1.  The warning message is not the place to be trying to explain all the
>> > details.
>>
>> OK, updated patch attached.
>
> Patch applied.

I only just noticed this item when I read the release notes.  Should
we bother warning when used on an unlogged table?

-- 
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Re: [HACKERS] Hash index creation warning

2014-10-18 Thread Bruce Momjian
On Fri, Oct 17, 2014 at 02:36:55PM -0400, Bruce Momjian wrote:
> On Fri, Oct 17, 2014 at 12:56:52PM -0400, Tom Lane wrote:
> > David G Johnston  writes:
> > > The question is whether we explain the implications of not being 
> > > WAL-logged
> > > in an error message or simply state the fact and let the documentation
> > > explain the hazards - basically just output:
> > > "hash indexes are not WAL-logged and their use is discouraged"
> > 
> > +1.  The warning message is not the place to be trying to explain all the
> > details.
> 
> OK, updated patch attached.

Patch applied.

-- 
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  EnterpriseDB http://enterprisedb.com

  + Everyone has their own god. +


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Re: [HACKERS] Hash index creation warning

2014-10-17 Thread Bruce Momjian
On Fri, Oct 17, 2014 at 12:56:52PM -0400, Tom Lane wrote:
> David G Johnston  writes:
> > The question is whether we explain the implications of not being WAL-logged
> > in an error message or simply state the fact and let the documentation
> > explain the hazards - basically just output:
> > "hash indexes are not WAL-logged and their use is discouraged"
> 
> +1.  The warning message is not the place to be trying to explain all the
> details.

OK, updated patch attached.

-- 
  Bruce Momjian  http://momjian.us
  EnterpriseDB http://enterprisedb.com

  + Everyone has their own god. +
diff --git a/doc/src/sgml/ref/create_index.sgml b/doc/src/sgml/ref/create_index.sgml
new file mode 100644
index e469b17..43df32f
*** a/doc/src/sgml/ref/create_index.sgml
--- b/doc/src/sgml/ref/create_index.sgml
*** Indexes:
*** 474,480 
  Also, changes to hash indexes are not replicated over streaming or
  file-based replication after the initial base backup, so they
  give wrong answers to queries that subsequently use them.
! For these reasons, hash index use is presently discouraged.
 

  
--- 474,481 
  Also, changes to hash indexes are not replicated over streaming or
  file-based replication after the initial base backup, so they
  give wrong answers to queries that subsequently use them.
! Hash indexes are also not properly restored during point-in-time
! recovery.  For these reasons, hash index use is presently discouraged.
 

  
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
new file mode 100644
index 8a1cb4b..3c1e90e
*** a/src/backend/commands/indexcmds.c
--- b/src/backend/commands/indexcmds.c
*** DefineIndex(Oid relationId,
*** 491,497 
  
  	if (strcmp(accessMethodName, "hash") == 0)
  		ereport(WARNING,
! (errmsg("hash indexes are not WAL-logged and thus are not crash-safe and cannot be used on standby servers")));
  
  	if (stmt->unique && !accessMethodForm->amcanunique)
  		ereport(ERROR,
--- 491,497 
  
  	if (strcmp(accessMethodName, "hash") == 0)
  		ereport(WARNING,
! (errmsg("hash indexes are not WAL-logged and their use is discouraged")));
  
  	if (stmt->unique && !accessMethodForm->amcanunique)
  		ereport(ERROR,
diff --git a/src/test/regress/expected/create_index.out b/src/test/regress/expected/create_index.out
new file mode 100644
index a2bef7a..8326e94
*** a/src/test/regress/expected/create_index.out
--- b/src/test/regress/expected/create_index.out
*** DROP TABLE array_gin_test;
*** 2238,2250 
  -- HASH
  --
  CREATE INDEX hash_i4_index ON hash_i4_heap USING hash (random int4_ops);
! WARNING:  hash indexes are not WAL-logged and thus are not crash-safe and cannot be used on standby servers
  CREATE INDEX hash_name_index ON hash_name_heap USING hash (random name_ops);
! WARNING:  hash indexes are not WAL-logged and thus are not crash-safe and cannot be used on standby servers
  CREATE INDEX hash_txt_index ON hash_txt_heap USING hash (random text_ops);
! WARNING:  hash indexes are not WAL-logged and thus are not crash-safe and cannot be used on standby servers
  CREATE INDEX hash_f8_index ON hash_f8_heap USING hash (random float8_ops);
! WARNING:  hash indexes are not WAL-logged and thus are not crash-safe and cannot be used on standby servers
  -- CREATE INDEX hash_ovfl_index ON hash_ovfl_heap USING hash (x int4_ops);
  --
  -- Test functional index
--- 2238,2250 
  -- HASH
  --
  CREATE INDEX hash_i4_index ON hash_i4_heap USING hash (random int4_ops);
! WARNING:  hash indexes are not WAL-logged and their use is discouraged
  CREATE INDEX hash_name_index ON hash_name_heap USING hash (random name_ops);
! WARNING:  hash indexes are not WAL-logged and their use is discouraged
  CREATE INDEX hash_txt_index ON hash_txt_heap USING hash (random text_ops);
! WARNING:  hash indexes are not WAL-logged and their use is discouraged
  CREATE INDEX hash_f8_index ON hash_f8_heap USING hash (random float8_ops);
! WARNING:  hash indexes are not WAL-logged and their use is discouraged
  -- CREATE INDEX hash_ovfl_index ON hash_ovfl_heap USING hash (x int4_ops);
  --
  -- Test functional index
diff --git a/src/test/regress/expected/enum.out b/src/test/regress/expected/enum.out
new file mode 100644
index fa23b52..1a61a5b
*** a/src/test/regress/expected/enum.out
--- b/src/test/regress/expected/enum.out
*** DROP INDEX enumtest_btree;
*** 383,389 
  -- Hash index / opclass with the = operator
  --
  CREATE INDEX enumtest_hash ON enumtest USING hash (col);
! WARNING:  hash indexes are not WAL-logged and thus are not crash-safe and cannot be used on standby servers
  SELECT * FROM enumtest WHERE col = 'orange';
col   
  
--- 383,389 
  -- Hash index / opclass with the = operator
  --
  CREATE INDEX enumtest_hash ON enumtest USING hash (col);
! WARNING:  hash indexes are not WAL-logged and their use is discourag

Re: [HACKERS] Hash index creation warning

2014-10-17 Thread Tom Lane
David G Johnston  writes:
> The question is whether we explain the implications of not being WAL-logged
> in an error message or simply state the fact and let the documentation
> explain the hazards - basically just output:
> "hash indexes are not WAL-logged and their use is discouraged"

+1.  The warning message is not the place to be trying to explain all the
details.

regards, tom lane


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Re: [HACKERS] Hash index creation warning

2014-10-17 Thread David G Johnston
Bruce Momjian wrote
> Now that we have the create hash index warning in 9.5, I realized that
> we don't warn about hash indexes with PITR, only crash recovery and
> streaming.  This patch fixes that.
> 
> Is the wording "cannot be used" too vague.  The CREATE INDEX manual
> page has the words "give wrong answers to queries", which might be
> better, but is kind of long for an error message.  Suggestions?

Something like the following is more specific without being more wordy:

"hash indexes are not WAL-logged: they are corrupted during recovery and
changes do not replicate to standby servers."

The question is whether we explain the implications of not being WAL-logged
in an error message or simply state the fact and let the documentation
explain the hazards - basically just output:

"hash indexes are not WAL-logged and their use is discouraged"

David J.




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[HACKERS] Hash index creation warning

2014-10-17 Thread Bruce Momjian
Now that we have the create hash index warning in 9.5, I realized that
we don't warn about hash indexes with PITR, only crash recovery and
streaming.  This patch fixes that.

Is the wording "cannot be used" too vague.  The CREATE INDEX manual
page has the words "give wrong answers to queries", which might be
better, but is kind of long for an error message.  Suggestions?

-- 
  Bruce Momjian  http://momjian.us
  EnterpriseDB http://enterprisedb.com

  + Everyone has their own god. +
diff --git a/doc/src/sgml/ref/create_index.sgml b/doc/src/sgml/ref/create_index.sgml
new file mode 100644
index e469b17..43df32f
*** a/doc/src/sgml/ref/create_index.sgml
--- b/doc/src/sgml/ref/create_index.sgml
*** Indexes:
*** 474,480 
  Also, changes to hash indexes are not replicated over streaming or
  file-based replication after the initial base backup, so they
  give wrong answers to queries that subsequently use them.
! For these reasons, hash index use is presently discouraged.
 

  
--- 474,481 
  Also, changes to hash indexes are not replicated over streaming or
  file-based replication after the initial base backup, so they
  give wrong answers to queries that subsequently use them.
! Hash indexes are also not properly restored during point-in-time
! recovery.  For these reasons, hash index use is presently discouraged.
 

  
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
new file mode 100644
index 8a1cb4b..03833d7
*** a/src/backend/commands/indexcmds.c
--- b/src/backend/commands/indexcmds.c
*** DefineIndex(Oid relationId,
*** 491,497 
  
  	if (strcmp(accessMethodName, "hash") == 0)
  		ereport(WARNING,
! (errmsg("hash indexes are not WAL-logged and thus are not crash-safe and cannot be used on standby servers")));
  
  	if (stmt->unique && !accessMethodForm->amcanunique)
  		ereport(ERROR,
--- 491,497 
  
  	if (strcmp(accessMethodName, "hash") == 0)
  		ereport(WARNING,
! (errmsg("hash indexes are not WAL-logged and thus are not crash-safe and cannot be used for point-in-time recovery or on standby servers")));
  
  	if (stmt->unique && !accessMethodForm->amcanunique)
  		ereport(ERROR,
diff --git a/src/test/regress/expected/create_index.out b/src/test/regress/expected/create_index.out
new file mode 100644
index a2bef7a..11325e4
*** a/src/test/regress/expected/create_index.out
--- b/src/test/regress/expected/create_index.out
*** DROP TABLE array_gin_test;
*** 2238,2250 
  -- HASH
  --
  CREATE INDEX hash_i4_index ON hash_i4_heap USING hash (random int4_ops);
! WARNING:  hash indexes are not WAL-logged and thus are not crash-safe and cannot be used on standby servers
  CREATE INDEX hash_name_index ON hash_name_heap USING hash (random name_ops);
! WARNING:  hash indexes are not WAL-logged and thus are not crash-safe and cannot be used on standby servers
  CREATE INDEX hash_txt_index ON hash_txt_heap USING hash (random text_ops);
! WARNING:  hash indexes are not WAL-logged and thus are not crash-safe and cannot be used on standby servers
  CREATE INDEX hash_f8_index ON hash_f8_heap USING hash (random float8_ops);
! WARNING:  hash indexes are not WAL-logged and thus are not crash-safe and cannot be used on standby servers
  -- CREATE INDEX hash_ovfl_index ON hash_ovfl_heap USING hash (x int4_ops);
  --
  -- Test functional index
--- 2238,2250 
  -- HASH
  --
  CREATE INDEX hash_i4_index ON hash_i4_heap USING hash (random int4_ops);
! WARNING:  hash indexes are not WAL-logged and thus are not crash-safe and cannot be used for point-in-time recovery or on standby servers
  CREATE INDEX hash_name_index ON hash_name_heap USING hash (random name_ops);
! WARNING:  hash indexes are not WAL-logged and thus are not crash-safe and cannot be used for point-in-time recovery or on standby servers
  CREATE INDEX hash_txt_index ON hash_txt_heap USING hash (random text_ops);
! WARNING:  hash indexes are not WAL-logged and thus are not crash-safe and cannot be used for point-in-time recovery or on standby servers
  CREATE INDEX hash_f8_index ON hash_f8_heap USING hash (random float8_ops);
! WARNING:  hash indexes are not WAL-logged and thus are not crash-safe and cannot be used for point-in-time recovery or on standby servers
  -- CREATE INDEX hash_ovfl_index ON hash_ovfl_heap USING hash (x int4_ops);
  --
  -- Test functional index
diff --git a/src/test/regress/expected/enum.out b/src/test/regress/expected/enum.out
new file mode 100644
index fa23b52..47ac5a6
*** a/src/test/regress/expected/enum.out
--- b/src/test/regress/expected/enum.out
*** DROP INDEX enumtest_btree;
*** 383,389 
  -- Hash index / opclass with the = operator
  --
  CREATE INDEX enumtest_hash ON enumtest USING hash (col);
! WARNING:  hash indexes are not WAL-logged and thus are not crash-safe and cannot be used on standby servers
  SELECT * FROM enumtest WHERE co