Adxftl

adxftl is a variable used to set a read grouping factor in a number of records.

This information is managed by the For instruction to optimize the database access time.

Syntax

adxftl

• When its value is 1 or less, the instruction For works without grouping.
• When its value is equal to N greater than 1, the instruction For transfers blocks of N records from the database.

When a Read loop is executed with record-grouping, the number of back and forth movements between the database and the engine are reduced.

You should avoid Read operations within a For loop to keep the full benefit of this optimization. If the Read is done on tables that are linked to the main table inwhich the For is performed, it is possible to use a Link instruction that has good performances especially if the join is a strict join (with the ~= operator).

In most cases, a recommended value for adxftl is 10, which gives a good optimization of the read operations without creating an overhead when reading small tables.

The engine does not carry out any read optimizing on tables including CLOBs or BLOBs.

Example

 # Recommended valueadxftl=10

See also

For, Read, adxwrb.