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* Crash with PostgreSQL 7.4
@ 2004-02-25 23:30 Peter Eisentraut
  2004-02-26 17:15 ` Fernando Nasser
  0 siblings, 1 reply; 4+ messages in thread
From: Peter Eisentraut @ 2004-02-25 23:30 UTC (permalink / raw)
  To: rhdb-explain

[-- Attachment #1: Type: text/plain, Size: 886 bytes --]

I have used rhdb-explain from the tag RHDB-3-0 and ran the following
query against an empty PostgreSQL 7.4.1 database:

select * from pg_tables;

This causes a null pointer exception.  The output on the console is

java.lang.NullPointerException
        at com.redhat.rhdb.explain.ExplainParserV73.addQual(ExplainParserV73.java:796)
        at com.redhat.rhdb.explain.ExplainParserV73.buildExplainTree(ExplainParserV73.java:343)
        at com.redhat.rhdb.explain.ExplainParserV73.explain(ExplainParserV73.java:187)
        at com.redhat.rhdb.explain.Explain$ExplainThread.run(Explain.java:298)

The reason is that the parser code only knows "Hash Join" but PG 7.4
emits a "Hash Left Join" in this case.

Attached is a patch that kind of papers over this issue by ignoring
"Left" and other possible hash-join attributes.  Eventually one might
want to show this distinction to the user.

[-- Attachment #2: rhdb-explain-hashleftjoin.patch --]
[-- Type: text/x-diff, Size: 583 bytes --]

*** ../src/rhdb/guitools/rhdb-explain/src/com/redhat/rhdb/explain/ExplainParserV73.java	2003-11-21 19:30:47.000000000 +0100
--- src/com/redhat/rhdb/explain/ExplainParserV73.java	2004-02-25 21:06:04.000000000 +0100
***************
*** 447,452 ****
--- 447,460 ----
  			{
  				String next = strtok.nextToken();
  
+ 				if (next.equals("Left")
+ 				    || next.equals("Right")
+ 				    || next.equals("Full")
+ 				    || next.equals("IN"))
+ 				{
+ 					next = strtok.nextToken();
+ 				}
+ 
  				if (next.equals("Join"))
  				{
  					node.setType(ExplainTreeNode.NODE_JOIN);

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: Crash with PostgreSQL 7.4
  2004-02-25 23:30 Crash with PostgreSQL 7.4 Peter Eisentraut
@ 2004-02-26 17:15 ` Fernando Nasser
  2004-02-26 17:43   ` Peter Eisentraut
  0 siblings, 1 reply; 4+ messages in thread
From: Fernando Nasser @ 2004-02-26 17:15 UTC (permalink / raw)
  To: Peter Eisentraut; +Cc: rhdb-explain

Hi Peter,

Thank you for your report.

Apparently these nodes were added since I last looked at it.  I thought I had 
added all the new nodes....

I wonder if this is not already in the rdhb-explain cvs tip.  Originally 
RHDB-3-0 was a 7.3.x release and I may have avoided changing the branch.

Best regards,
Fernando



Peter Eisentraut wrote:
> I have used rhdb-explain from the tag RHDB-3-0 and ran the following
> query against an empty PostgreSQL 7.4.1 database:
> 
> select * from pg_tables;
> 
> This causes a null pointer exception.  The output on the console is
> 
> java.lang.NullPointerException
>         at com.redhat.rhdb.explain.ExplainParserV73.addQual(ExplainParserV73.java:796)
>         at com.redhat.rhdb.explain.ExplainParserV73.buildExplainTree(ExplainParserV73.java:343)
>         at com.redhat.rhdb.explain.ExplainParserV73.explain(ExplainParserV73.java:187)
>         at com.redhat.rhdb.explain.Explain$ExplainThread.run(Explain.java:298)
> 
> The reason is that the parser code only knows "Hash Join" but PG 7.4
> emits a "Hash Left Join" in this case.
> 
> Attached is a patch that kind of papers over this issue by ignoring
> "Left" and other possible hash-join attributes.  Eventually one might
> want to show this distinction to the user.
> 
> 
> ------------------------------------------------------------------------
> 
> *** ../src/rhdb/guitools/rhdb-explain/src/com/redhat/rhdb/explain/ExplainParserV73.java	2003-11-21 19:30:47.000000000 +0100
> --- src/com/redhat/rhdb/explain/ExplainParserV73.java	2004-02-25 21:06:04.000000000 +0100
> ***************
> *** 447,452 ****
> --- 447,460 ----
>   			{
>   				String next = strtok.nextToken();
>   
> + 				if (next.equals("Left")
> + 				    || next.equals("Right")
> + 				    || next.equals("Full")
> + 				    || next.equals("IN"))
> + 				{
> + 					next = strtok.nextToken();
> + 				}
> + 
>   				if (next.equals("Join"))
>   				{
>   					node.setType(ExplainTreeNode.NODE_JOIN);


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: Crash with PostgreSQL 7.4
  2004-02-26 17:15 ` Fernando Nasser
@ 2004-02-26 17:43   ` Peter Eisentraut
  2004-02-26 18:57     ` Fernando Nasser
  0 siblings, 1 reply; 4+ messages in thread
From: Peter Eisentraut @ 2004-02-26 17:43 UTC (permalink / raw)
  To: Fernando Nasser; +Cc: rhdb-explain

Fernando Nasser wrote:
> I wonder if this is not already in the rdhb-explain cvs tip. 
> Originally RHDB-3-0 was a 7.3.x release and I may have avoided
> changing the branch.

AFAICT, the code in the head and in the RHDB-3-0 branch is all the same.  
Also, the RHDB-3-0 code does contain a comment that it was modified for 
7.4, so I figured it was a plain oversight.

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: Crash with PostgreSQL 7.4
  2004-02-26 17:43   ` Peter Eisentraut
@ 2004-02-26 18:57     ` Fernando Nasser
  0 siblings, 0 replies; 4+ messages in thread
From: Fernando Nasser @ 2004-02-26 18:57 UTC (permalink / raw)
  To: Peter Eisentraut; +Cc: rhdb-explain, David Jee

Peter Eisentraut wrote:
> Fernando Nasser wrote:
> 
>>I wonder if this is not already in the rdhb-explain cvs tip. 
>>Originally RHDB-3-0 was a 7.3.x release and I may have avoided
>>changing the branch.
> 
> 
> AFAICT, the code in the head and in the RHDB-3-0 branch is all the same.  
> Also, the RHDB-3-0 code does contain a comment that it was modified for 
> 7.4, so I figured it was a plain oversight.
> 
> 

Probably.  When I've adapted rhdb-explain for 7.4 there was no real 7.4 yet, 
just the tip of the development cvs branch.  Maybe these node types where added 
after I did that.


I will make the correction and see if an update can be packaged for Fedora.


Thanks again for the report.

Regards,
Fernando

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2004-02-26 18:57 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2004-02-25 23:30 Crash with PostgreSQL 7.4 Peter Eisentraut
2004-02-26 17:15 ` Fernando Nasser
2004-02-26 17:43   ` Peter Eisentraut
2004-02-26 18:57     ` Fernando Nasser

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