Master Detail performance problem

Question

I have a demo master detail application which was built using the Application Express Wizard (APEX v3.2) which is performing badly under a particular situation.
The master detail is a workers table (46000 rows, pk index on id) and a licence table (48000 rows, fk index on wkr_id)
The generated application opens with a multi row report from a workers table. Clicking on the edit button on a worker record takes you to a master detail page which is the worker record and one or more licence records.
If the report page is run and you click the edit button to go to the master detail page, then you click on the next and previous records buttons the performance is fast - around 0.3 seconds.
However if you use a search term in the report page to find workers by name. The report page renders quite fast but then clicking on the edit button to go to the master detail worker record page is slow - around 5.5 seconds at best. This scales badly too. Clicking next and previous buttons at this point is similarly very slow.
4 sql statements are appearing in V$SQLAREA when the next button is clicked as follows:
1. SELECT "ID", LEAD("ID",1) over (order by "ID") next, LAG("ID",1) over (order by "ID") prev
FROM "PROD"."WORKERS"
2. SELECT "ID","LIC_ID","SURNAME", "FIRST_NAME","OTHER_NAME",
FROM "PROD"."WORKERS" WHERE "ID" = :B1 FOR UPDATE;
3. SELECT "ID","LIC_ID","SURNAME", "FIRST_NAME","OTHER_NAME",
FROM "PROD"."WORKERS" WHERE "ID" = :B1;
4. SELECT NULL "CHECK$01", "ID" "ID", "WKR_ID" "WKR_ID", "LIC_NO" "LIC_NO", "ISSUING_STATE" "ISSUING_STATE"
FROM ( SELECT /*+(WORKER_LICENCES eli_wli_wkr_fk) */
"ID", "WKR_ID", "LIC_NO", "ISSUING_STATE"
FROM "PROD"."WORKER_LICENCES"
WHERE "WKR_ID" = :P2_ID)
These queries run like lightning when executed directly on the database and are as generated by the APEX wizard.
The same application generated in Oracle Forms 10 on the same database is super fast (< 0.2 seconds.)
Can anyone advise where the problem may lie.
Thanks
Phil Gray
Edited by: graypz on Aug 18, 2009 6:50 PM

Answer 1

Thanks for that Andy
This got me to thinking. The number of columns that I have shown is pruned down drastically from the actual 50 columns in the table - which would make indexing out of the question.
The classic presentation of the home page of the generated application allows a search field which does searching in any column for a search term :P1_REPORT_SEARCH. The region source query has a monster "where clause" to cater for that, something like this:
where (
instr(upper("LIC_ID"),upper(nvl(:P1_REPORT_SEARCH,"LIC_ID"))) > 0 or
instr(upper("SURNAME"),upper(nvl(:P1_REPORT_SEARCH,"SURNAME"))) > 0 or
instr(upper("FIRST_NAME"),upper(nvl(:P1_REPORT_SEARCH,"FIRST_NAME"))) > 0 ... etc for the whole 50 columns
Sure enough, when I run that query direct in the database it performs badly - around 4.5 seconds.
My first cut of a workaround is to restrict the columns that can be searched to those with an index (LIC_ID, SURNAME) and to remove the rest of the generated where clause. Then to edit the P1_REPORT_SEARCH label to say "Search for Lic Id or Surname".
This brings about an immediate sudden increase in speed of the query.
The next part is still unresolved. The master detail form "next" "previous" buttons do not perform too well - and the records are not in context of the search that was run on the home page. My workaround is to remove the buttons as I don't have enough knowledge to attack that yet.
I may be expecting too much of the APEX wizard, but hopefully someone can direct me to a way of resolving this.
Regards
Phil Gray