SQL/MP Reference Manual

HP NonStop SQL/MP Reference Manual—523352-013
C-77
CONTROL TABLE Directive
CONTROL TABLE Directive
CONTROL TABLE is a DCL directive that specifies performance-related options for
DML accesses to a table or view. CONTROL TABLE affects decisions the SQL
compiler makes about how to execute DML statements.
CONTROL TABLE affects the selection of access paths, join methods, join sequences,
lock types, and block buffering and block splitting algorithms. CONTROL TABLE also
specifies whether to open indexes and partitions at the initial access to a table,
whether to checkpoint unaudited writes, and what to do when encountering locked data
or unavailable partitions.
table
is the name of the table to which the control options apply (or an equivalent
DEFINE), exactly as the table name (or DEFINE name) appears in subsequent
references that are to be affected by the control options.
For example, if table is a fully qualified Guardian name, the control options apply
to subsequent references that use the same fully qualified Guardian name. The
{ table [ AS cor ] }
CONTROL TABLE { view [ AS cor ] [BASETABLE btcor] }
{ * }
[| ACCESS PATH { SYSTEM | PRIMARY | INDEX index } |]
[| [MDAM ON [USE {value|DEFAULT} [KEY] COLUMN[S]] |]
[| [ACCESS { SPARSE | DENSE | SYSTEM}] ] |]
[| |]
[| JOIN METHOD { NESTED | [KEY SEQUENCED] MERGE | |]
[| HASH | SYSTEM } |]
[| |]
[| JOIN SEQUENCE { SYSTEM | sequence-number } |]
[| |]
[| MDAM { OFF | ENABLE } |]
[| |]
[| OPEN { ALL | ACCESSED } [ PARTITIONS ] |]
[| |]
[| { RETURN | WAIT } IF LOCKED |]
[| |]
[| SEQUENTIAL [ INSERT|READ|UPDATE ] {ON|OFF|ENABLE} |]
[| |]
[| SEQUENTIAL BLOCKSPLIT [ FOR INSERT ] {ON|ENABLE} |]
[| |]
[| { SKIP | STOP AT } UNAVAILABLE PARTITION |]
[| |]
[| SYNCDEPTH { 0 | 1 } |]
[| |]
[| TABLELOCK { OFF | ON | ENABLE } |]
[| |]
[| TIMEOUT { value | DEFAULT } [ SECOND[S] ] |]