rowcount
Defines the number of rows that the Sybase server keeps in its memory per request.
Syntax
USYS$SYB_PARAMS { =
}
rowcount=Number
Arguments
-
Number—number of rows that the Sybase server keeps in its memory per request; must be a multiple of
step size
Description
Use
rowcount only in combination with same select option.
If
rowcount is not set, Sybase retrieves all the results before returning the
first records (as determined by the step size option), which can be very
time-consuming.
Setting
rowcount limits the number of requested results to the step size. After the
specified number of rows have been retrieved and the next step in the hitlist is requested, the
same SQL query is repeated, with rowcount increased by the specified number. Thus,
if rowcount 30 is specified, it rowcount becomes 60, then 90,
120, and so on. All rows that were fetched before are fetched again, but are skipped when the
records are retrieved, so only the newly fetched records are retrieved.
To fine-tune performance you need to balance the step size and the row count:
-
To improve Uniface performance, keep
step sizesmall androwcounthigh -
To improve the Sybase server performance, lower the
rowcount.
Tuning Performance
USYS$SYB_PARAMS same select, stepsize=15, rowcount=30
