SQL Programming Manual for TAL

Program Compilation and Execution
HP NonStop SQL Programming Manual for TAL—527887-001
5-27
Understanding the Run-Time Timestamp Check
If TABLEA is open when you execute the ALTER TABLE statement, the system
closes the table. The next time the SQL statement is executed, the SQL executor
reopens TABLEA, which forces the timestamp check and the statement to be
recompiled.
Figure 5-7
shows this run-time object definition check.
Figure 5-7. Run-Time Checks and Automatic SQL Recompilation
VST0507.vsd
Catalog
Timestamp programa
FROM tablea . . .
SELECT . . .
SQL Object Code
. . .
Timestamp programa
Automatic
SQL
Recompilation
Rewrites Area
SQL Executor
SQL Object Code
(copy)
. . .
SELECT . . .
FROM tablea . . .
Timestamp programa