Re: Crash with PostgreSQL 7.4

[Fernando Nasser <fnasser at redhat dot com>]

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);