Thread: Graphical explain plan sometimes shows "using" for the index name
This is a bug in the graphical explain plan in the pgAdmin III Query tool. In the graphical explain plan if your query is ordering with the help of an index and the order is "Descending" then the graphical explain plan just says "using" as the index name. If the sort order is ascending then the correct index name is displayed. Here are the relevant lines from the textual output from explain: DESC -> Index Scan Backward using idx_name on table_name ASC -> Index Scan using idx_name on table_name This may be because the code for getting the index name is grabbing the 4th word and does not check to see if the word "Backward" was added to the line, in which case the 5th word should be used. My Environment: pgAdmin III 1.4.3 Default config, downloaded precomplied binary for windows Windows XP Postgresql 8.1.4 To reproduce the problem is simple, just be sure to order by an indexed column and then click the Explain Query button: select * from table_name order by indexed_col asc limit 1 select * from table_name order by indexed_col desc limit 1 I did a mailing list search but didn't see anyone else reporting this. If it's a newly found bug then I'd greatly appreciate it if someone could fix this. I use the graphical query explain tool a lot, I find it to be very useful when designing new queries. Thanks, Brendan
Re: Graphical explain plan sometimes shows "using" for the index name
From
"Andy Shellam (Mailing Lists)"
Date:
Is this still present in the latest version of PgAdmin? v1.6.2 is the current stable version. Regards, Andy. O'Shea, Brendan wrote: > This is a bug in the graphical explain plan in the pgAdmin III Query > tool. In the graphical explain plan if your query is ordering with the > help of an index and the order is "Descending" then the graphical > explain plan just says "using" as the index name. If the sort order is > ascending then the correct index name is displayed. Here are the > relevant lines from the textual output from explain: > > > DESC > -> Index Scan Backward using idx_name on table_name > ASC > -> Index Scan using idx_name on table_name > > This may be because the code for getting the index name is grabbing the > 4th word and does not check to see if the word "Backward" was added to > the line, in which case the 5th word should be used. > > My Environment: > pgAdmin III 1.4.3 > Default config, downloaded precomplied binary for windows > Windows XP > Postgresql 8.1.4 > > > To reproduce the problem is simple, just be sure to order by an indexed > column and then click the Explain Query button: > > select * from table_name order by indexed_col asc limit 1 > select * from table_name order by indexed_col desc limit 1 > > > I did a mailing list search but didn't see anyone else reporting this. > If it's a newly found bug then I'd greatly appreciate it if someone > could fix this. I use the graphical query explain tool a lot, I find it > to be very useful when designing new queries. > > Thanks, > Brendan > > ---------------------------(end of broadcast)--------------------------- > TIP 1: if posting/reading through Usenet, please send an appropriate > subscribe-nomail command to majordomo@postgresql.org so that your > message can get through to the mailing list cleanly > > !DSPAM:37,45c775e918511302212047! > > >
Yes, the bug is in the latest v1.6.2 as well. I'm continuing to use the older 1.4.3 version because I like the fact that the output pane retains column sizing when you repeatedly run the same query. Brendan > -----Original Message----- > From: Andy Shellam (Mailing Lists) > [mailto:andy.shellam-lists@mailnetwork.co.uk] > Sent: Monday, February 05, 2007 1:35 PM > To: O'Shea, Brendan > Cc: pgadmin-support@postgresql.org > Subject: Re: [pgadmin-support] Graphical explain plan > sometimes shows "using" for the index name > > Is this still present in the latest version of PgAdmin? > v1.6.2 is the current stable version. > > Regards, > > Andy. > > > O'Shea, Brendan wrote: > > This is a bug in the graphical explain plan in the pgAdmin > III Query > > tool. In the graphical explain plan if your query is ordering with > > the help of an index and the order is "Descending" then the > graphical > > explain plan just says "using" as the index name. If the > sort order > > is ascending then the correct index name is displayed. > Here are the > > relevant lines from the textual output from explain: > > > > > > DESC > > -> Index Scan Backward using idx_name on table_name ASC > > -> Index Scan using idx_name on table_name > > > > This may be because the code for getting the index name is grabbing > > the 4th word and does not check to see if the word "Backward" was > > added to the line, in which case the 5th word should be used. > > > > My Environment: > > pgAdmin III 1.4.3 > > Default config, downloaded precomplied binary for windows > Windows XP > > Postgresql 8.1.4 > > > > > > To reproduce the problem is simple, just be sure to order by an > > indexed column and then click the Explain Query button: > > > > select * from table_name order by indexed_col asc limit 1 select * > > from table_name order by indexed_col desc limit 1 > > > > > > I did a mailing list search but didn't see anyone else > reporting this. > > If it's a newly found bug then I'd greatly appreciate it if someone > > could fix this. I use the graphical query explain tool a > lot, I find > > it to be very useful when designing new queries. > > > > Thanks, > > Brendan > > > > ---------------------------(end of > > broadcast)--------------------------- > > TIP 1: if posting/reading through Usenet, please send an appropriate > > subscribe-nomail command to majordomo@postgresql.org > so that your > > message can get through to the mailing list cleanly > > > > !DSPAM:37,45c775e918511302212047! > > > > > > >
O'Shea, Brendan wrote: > This is a bug in the graphical explain plan in the pgAdmin III Query > tool. In the graphical explain plan if your query is ordering with the > help of an index and the order is "Descending" then the graphical > explain plan just says "using" as the index name. If the sort order is > ascending then the correct index name is displayed. Here are the > relevant lines from the textual output from explain: Thanks Brendan - fixed for 1.6.3. Regards, Dave.