SQL/MX 2.x Database and Application Migration Guide (G06.23+, H06.04+, J06.03+)

Converting SQL/MP Applications to SQL/MX
Applications
HP NonStop SQL/MX Database and Application Migration Guide—540435-005
10-17
Data Control Language (DCL) Statements
Data Control Language (DCL) Statements
Some SQL/MP DCL statements are supported in NonStop SQL/MX. Table 10-2 lists
the SQL/MP DCL statements that are supported in NonStop SQL/MX and describes
the syntax differences:
CONTROL TABLE Directives
In NonStop SQL/MP, you can use the CONTROL TABLE directive for many purposes
but mainly to specify performance-related options for DML accesses to a table or view.
In NonStop SQL/MP, the CONTROL TABLE directive affects decisions the SQL
compiler makes about how to execute DML statements. In NonStop SQL/MX, because
the compiler and executor have been redesigned, many directives are no longer
necessary.
In NonStop SQL/MP, you can enter multiple options on a single CONTROL TABLE
statement. In NonStop SQL/MX, you can enter only one option on a single CONTROL
TABLE statement.
Table 10-3
lists which SQL/MP controls are not implemented in NonStop SQL/MX or
are implemented differently:
Table 10-2. SQL/MX and SQL/MP DCL Statements
SQL/MP DCL
Statements
Implemented
in SQL/MX? Comments
CONTROL EXECUTOR No PARALLEL EXECUTION is ON by default in
NonStop SQL/MX.
CONTROL QUERY Changed See CONTROL QUERY Directives
on
page 10-19.
CONTROL TABLE Changed See CONTROL TABLE Directives
on
page 10-17; also see Forcing Query Execution
Plans on page 10-59.
FREE RESOURCES No Remove this statement from the source code.
Instead, use the UNLOCK TABLE and CLOSE
statements, or use the COMMIT WORK and
ROLLBACK WORK statements to perform all
FREE RESOURCES operations.
LOCK TABLE Yes No changes are required for NonStop SQL/MX.
UNLOCK TABLE Yes No changes are required for NonStop SQL/MX.