How to Imporve Report Perfomance

[mrPela]

I developed a report and it takes literally 30 minutes to open up. How do I
improve performance. The data set is a local table that is not on the back
end of the database. However there are about 4 sub forms on the report. These
subforms are all queries. I requery the subform queries prior to opening up
the report. What are some things that I can do to make this report open a lot
quicker?

 

[Roger Carlson]

It depends an awful lot on things you haven't mentioned. Indexing, table
size, the construction of the queries, etc.

My first suggestion is to check that the table is indexed properly. Any
field that participates in a join, sort, or where condition is a candidate
for indexing.

If that doesn't help, you can make your 4 subform queries into MakeTable
queries, base the subforms on the temp tables created, and run them before
you run the report. You can do this all in code (say in the click event of
a button) to make sure the queries are run before the report is opened.

--
--Roger Carlson
MS Access MVP
Access Database Samples: www.rogersaccesslibrary.com
Want answers to your Access questions in your Email?
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[mrPela]

Thanks Roger. When you say indexing the tables, you basically mean create
relationships using the manager or simply create a primary key in the table?

It depends an awful lot on things you haven't mentioned. Indexing, table
size, the construction of the queries, etc.

My first suggestion is to check that the table is indexed properly. Any
field that participates in a join, sort, or where condition is a candidate
for indexing.

If that doesn't help, you can make your 4 subform queries into MakeTable
queries, base the subforms on the temp tables created, and run them before
you run the report. You can do this all in code (say in the click event of
a button) to make sure the queries are run before the report is opened.

I developed a report and it takes literally 30 minutes to open up. How do I
improve performance. The data set is a local table that is not on the back

[quoted text clipped - 5 lines]

lot
quicker?

 

[Roger Carlson]

Neither. Well, sort of. A primary key is an index, and you should have
one. Access *should* create indexes on the fields involved in a
relationship, *if* you create it in the Relationship Window with referential
integrity.

However, aside from that, you can index fields individually or combinations
of fields. As a first step, index any field that participates in a Sort or
a Criteria (WHERE clause). You can do this in the Design View of the
table. In the Properties a the bottom of the window, choose Indexed
(duplicates OK). That will create a single field index. Multiple field
indexes are a little more complicated and can sometimes even reduce
performance if created improperly, so start with single-field indexing.

You can read more about indexes here:
http://rogersaccessblog.blogspot.com/2008/12/access-101-what-is-index.html

--
--Roger Carlson
MS Access MVP
Access Database Samples: www.rogersaccesslibrary.com
Want answers to your Access questions in your Email?
Free subscription:
http://peach.ease.lsoft.com/scripts/wa.exe?SUBED1=ACCESS-L

Thanks Roger. When you say indexing the tables, you basically mean create
relationships using the manager or simply create a primary key in the
table?

It depends an awful lot on things you haven't mentioned. Indexing, table
size, the construction of the queries, etc.

My first suggestion is to check that the table is indexed properly. Any
field that participates in a join, sort, or where condition is a candidate
for indexing.

If that doesn't help, you can make your 4 subform queries into MakeTable
queries, base the subforms on the temp tables created, and run them before
you run the report. You can do this all in code (say in the click event
of
a button) to make sure the queries are run before the report is opened.

I developed a report and it takes literally 30 minutes to open up. How do
I
improve performance. The data set is a local table that is not on the
back

[quoted text clipped - 5 lines]

lot
quicker?

 

[John Spencer]

First of all, there is no good reason to run a query before opening a report.
The report and the sub-reports will call the queries independently. So
executing the queries just wastes time.

Next, I would not use sub FORMS on a report. I would use sub REPORTS on a
report.

Check that the fields involved in limiting the records or sorting the records
are indexed. Also make sure the indexes for the fields used in the links
between the main report and the sub-reports are indexed

John Spencer
Access MVP 2002-2005, 2007-2010
The Hilltop Institute
University of Maryland Baltimore County

 

[mrPela]

John - I am using subReports, I apologize. I wasn't querying the actual query
associated with the sub report. However, there are maybe 2 or 3 queries that
support the query for a sub Report. Therefore the 1 query that supports the
query is the one I'm updating which in theory I would think would make the
main query easier to open, NO???

 

[John Spencer]

What do you mean by updating the query? Are you just executing a select
query? If so, that should have minimal effect on the report's speed. The
effect it MIGHT have would be to cause some caching of the results.

The query will run when the report opens, so there is really no reason to
execute the query unless it is
== Updating a table
== deleting records from a table
== adding records to a table.

One thing that sometimes can help if you have very complex queries is to dump
the data into tables and then use the tables. This is very seldom the best
solution but there are a few cases with very complex reports that I do this
for performance reasons.



John Spencer
Access MVP 2002-2005, 2007-2010
The Hilltop Institute
University of Maryland Baltimore County

 

[mrPela]

Yes' It's a simple select query. The reason I do it is because I want to
limit the results to only a specific group. There are thousands of records,
and I only need records for a specific group of records. So in the query that
I'm running prior, I identify which group I want.

are you telling me that doesn't have an affect?

Also - my db is split (front end/back end). However it's not an .MDE. If I
were to make it one, how would that improve this performance issue I'm having.

John - I am using subReports, I apologize. I wasn't querying the actual query
associated with the sub report. However, there are maybe 2 or 3 queries that
support the query for a sub Report. Therefore the 1 query that supports the
query is the one I'm updating which in theory I would think would make the
main query easier to open, NO???

First of all, there is no good reason to run a query before opening a report.
The report and the sub-reports will call the queries independently. So

[quoted text clipped - 18 lines]

 

[John Spencer]

Making it an mde would have almost zero effect on the speed.

Yes, running the query before hand should have NO effect on the speed of the
report. Try it without running the query first and see if you get any change.

As an experiment - make a copy of the report and remove the sub-reports. How
fast is it?

Now make a copy and remove three of the four sub-reports? How fast is it?

Repeat for all the sub-reports and see if any specific sub-report is the
culprit. If so, work on speeding that up.

Sub-reports can slow down a report significantly. Without being able to
actually see the report it is difficult to tell you what the exact problem is
or could be.

John Spencer
Access MVP 2002-2005, 2007-2010
The Hilltop Institute
University of Maryland Baltimore County

Yes' It's a simple select query. The reason I do it is because I want to
limit the results to only a specific group. There are thousands of records,
and I only need records for a specific group of records. So in the query that
I'm running prior, I identify which group I want.

are you telling me that doesn't have an affect?

Also - my db is split (front end/back end). However it's not an .MDE. If I
were to make it one, how would that improve this performance issue I'm having.

John - I am using subReports, I apologize. I wasn't querying the actual query
associated with the sub report. However, there are maybe 2 or 3 queries that
support the query for a sub Report. Therefore the 1 query that supports the
query is the one I'm updating which in theory I would think would make the
main query easier to open, NO???

First of all, there is no good reason to run a query before opening a report.
The report and the sub-reports will call the queries independently. So

[quoted text clipped - 18 lines]

the report. What are some things that I can do to make this report open a lot
quicker?