Query Speed Is Slower with ORDER BY Clause

• Microsoft FoxPro for Macintosh, versions 2.5x 2.6
• Microsoft Visual FoxPro for Windows, version 3.0
• Microsoft FoxPro for Windows, versions 2.5x, 2.6x
• Microsoft FoxPro for MS-DOS, versions 2.5x, 2.6x

SUMMARY

A query with an ORDER BY clause will be considerably slower than the same query without the ORDER BY clause.

MORE INFORMATION

The query times will vary based on the size of the database queried and the hardware involved. However, the times illustrated below show a considerable difference between querying with and without an ORDER BY clause.

When an ORDER BY clause is used, a new database is being generated by the query. Display status will show "table in use" as a table with a .TMP extension. Without the ORDER BY clause, the original database is used to generate the cursor query. Display status will show "table in use as the original table."

Steps to Reproduce Behavior

1. Open a database with 10,000 records or more and open an RQBE window.

2. Make sure an index exists for the field on which the query will be based, and then query without an ORDER BY clause. (In our test with a 10,000-record database, the query time shown in the status bar was 0.10 seconds.)

3. Query with an ORDER BY clause based on a different field. (In our test on the same database, the query time shown in the status bar was 17.68 seconds.)