Tabular Reports › TAB2 Command › Limit TAB2 Reports Using the TOP or BOTTOM Operand

Limit TAB2 Reports Using the TOP or BOTTOM Operand

The TOP and BOTTOM operands, like the FOR operand, limit reports organized by identifier to the number of identifiers specified.

However, the TOP and BOTTOM operands save storage because:

• The FOR operand tests identifiers only after all the data has been read and processed.
• The TOP and BOTTOM operands cause the Report Writer to test each record as it is read and discard records that do not qualify.

The TOP and BOTTOM operands are appropriate for ID options with many unique identifiers, such as TRANNUM.

The TAB command in the following example creates a report on the terminal response time of transactions. The TAB2 command shows the four transactions that had the longest lifetimes for each terminal. Processing similar commands using the FOR operand instead of the TOP operand would require much more storage.

TAB  TERMID TERM RESP
TAB2 TRANNUM TRAN LIFE TOP 4
END
RUN

A report like the following, shown in part, is generated:

TERM       TERM     TRAN     TRAN
ID         RESP    NUMBER    LIFE
-------- -------- -------- --------
CNSL      2.149   0000020   13.30
.                 0000019   0.016
.                 -------- --------
.                 SUMMARY   6.663
.                 -------- --------
ZA00      0.278   0000054   306.6
.                 0000058   0.647
.                 0000059   0.486
.                 0000053   0.264
.                 -------- --------
.                 SUMMARY   77.01
.                 -------- --------
0A19      0.202   0000297    2390
.                 0000613    2283
.                 0000427    2209
.                 0000229    1600
.                 -------- --------
.                 SUMMARY    2121
.                 -------- --------
  .         .        .         .
-------- -------- -------- --------
SUMMARY   0.275              4176
-------- -------- -------- --------
-------- -------- -------- --------