Operands related to SQL optimization

3) pd_optimize_level = SQL-optimization-option [,SQL-optimization-option]...

<identifier or unsigned integer>

Specifies SQL optimization options. For details about the SQL optimization options, see the HiRDB Version 8 UAP Development Guide. The SQL optimization option facilities are explained as follows.

SQL optimization option facility	Identifier	Unsigned integer	S	P
Forced nest-loop-join	"FORCE_NEST_JOIN"	4	Y	Y
Making multiple SQL objects	"SELECT_APSL"	10	Y	Y
Increasing the target floatable servers (back-end servers for fetching data)	"FLTS_INC_DATA_BES"	16	N	Y
Prioritized nest-loop-join	"PRIOR_NEST_JOIN"	32	Y	Y
Increasing the number of floatable server candidates	"FLTS_MAX_NUMBER"	64	N	Y
Priority of OR multiple index use	"PRIOR_OR_INDEXES"	128	Y	Y
Group processing, ORDER BY processing, and DISTINCT set function processing at the local back-end server	"SORT_DATA_BES"	256	N	Y
Suppressing use of AND multiple indexes	"DETER_AND_INDEXES"	512	Y	Y
Rapid grouping facility	"RAPID_GROUPING"	1024	Y	Y
Limiting the target floatable servers (back-end servers for fetching data)	"FLTS_ONLY_DATA_BES"	2048	N	Y
Separating data collecting servers	"FLTS_SEPARATE_COLLECT_SVR"	2064	N	Y
Suppressing index use (forced table scan)	"FORCE_TABLE_SCAN"	4096	Y	Y
Forcing use of multiple indexes	"FORCE_PLURAL_INDEXES"	32768	Y	Y
Suppressing creation of update-SQL work tables	"DETER_WORK_TABLE_FOR_UPDATE"	131072	Y	Y
Deriving search acceleration condition	"DERIVATIVE_COND"	262144	Y	Y
Applying key condition that includes scalar operation	"APPLY_ENHANCED_KEY_COND"	524288	Y	Y
Facility for batch acquisition from functions provided by plug-ins	"PICKUP_MULTIPLE_ROWS_PLUGIN"	1048576	Y	Y

S: HiRDB/Single Server

P: HiRDB/Parallel Server

Y: Specification is valid.

N: Specification is not applicable.

Operand specification methods

Select the SQL optimization options to be applied and specify their identifiers or unsigned integers. Although either identifiers or unsigned integers (computed values) can be used to specify options, the use of identifiers is usually recommended.

Using identifiers
To apply forced nest-loop-join and making multiple SQL objects, specify the following:
pd_optimize_level="FORCE_NEST_JOIN","SELECT_APSL"
Using unsigned integers
To apply forced nest-loop-join and making multiple SQL objects, specify the following:
pd_optimize_level=4,10
When you have upgraded from HiRDB Version 5.0 or older version
The total value specified in HiRDB Version 5.0 or older version is also valid. If there is no need to change the optimization option, you need not change the specification of this operand after upgrading to HiRDB Version 6 or a newer version. To add the optimization option, use the following example:
Example:
Forced nest-loop-join and making multiple SQL objects have been applied to HiRDB Version 5.0, and priority of OR multiple index use is to be newly added.
pd_optimize_level = 14,128
However, because this specification makes it difficult to identify the facilities being applied, use of identifier specification is recommended.

Operand rules

Identifiers and unsigned integers cannot be specified together.
Identifier specification
Enclose each SQL optimization option in quotation marks (").
If no SQL optimization option is used, specify NONE. When NONE and an identifier are both specified, the specification of NONE is invalid.
Identifiers can be specified in uppercase or lowercase letters.
Specifying the same identifier more than once is the same as specifying it once.
Unsigned integer specification
If you do not use the SQL optimization option explained here, specify 0. However, if both 0 and a non-zero unsigned integer are specified, the specification of 0 is ignored.
Specifying the same unsigned integer more than once is the same as specifying it once.

Specification guidelines: For specification guidelines, see SQL optimization option in the HiRDB Version 8 UAP Development Guide.

Notes

If SQL optimization is specified in an SQL statement, SQL optimization specification takes precedence over the specification in this operand. For details on SQL optimization specification, see the manual HiRDB Version 8 SQL Reference.
If SQL optimization is specified in an SQL statement (CREATE PROCEDURE, CREATE TYPE, ALTER PROCEDURE, CREATE TRIGGER, ALTER ROUTINE, or ALTER TRIGGER) inside a stored routine or trigger, the SQL optimization option inside the SQL statement takes precedence over the specification in this operand.

Relationship to other operands

When the pd_floatable_bes or pd_non_floatable_bes operand is specified in the front-end server definition, specification of "increasing the target floatable servers (back-end servers for fetching data)" and "limiting the target floatable servers (back-end servers for fetching data)" is invalid.
When KEY is specified for the pd_indexlock_mode operand, specification of "suppressing creation of update-SQL work tables" is invalid.

Relationship to client environment definition: The value of this operand can be different for each client. To change the value for a client, specify the PDSQLOPTLVL operand in the client environment definition. For details about the PDSQLOPTLVL operand, see the HiRDB Version 8 UAP Development Guide.

4) pd_additional_optimize_level = SQL-extension-optimizing-option [,SQL-extension-optimizing-option]...

<identifier or unsigned integer>

Specifies SQL extension optimizing options. For details about the SQL extension optimizing options, see the HiRDB Version 8 UAP Development Guide.

The SQL extension optimizing option facilities are described below.

SQL extension optimizing option facility	Identifier	Unsigned integer
Application of optimizing mode 2 based on cost	"COST_BASE_2"	1
Hash execution of a hash join or a subquery¹	"APPLY_HASH_JOIN"	2
Deterring of foreign server execution in SQL statement containing join^{1, 2}	"DETER_JOIN_SQL"	67108864
Forcing of foreign server execution in SQL statement containing direct product^{1, 2}	"FORCE_CROSS_JOIN_SQL"	134217728
Deterring of derivation of search acceleration condition that is generated unconditionally and that can be executed in foreign server^{1, 2}	"DETER_FSVR_DERIVATIVE_COND"	1073741824

¹ These items are valid when application of optimizing mode 2 based on cost is specified.

² These items are valid for searching a foreign table. Otherwise, they are invalid.

Operand specification methods

Select the SQL extension optimization options to be applied and specify their identifiers or unsigned integers. Although either identifiers or unsigned integers (computed values) can be used to specify options, the use of identifiers is usually recommended.

Using identifiers
To apply "application of optimizing mode 2 based on cost" and "hash execution of a hash join or a subquery," specify the following:
pd_additional_optimize_level= "COST_BASE_2", "APPLY_HASH_JOIN"
Using unsigned integers
To apply "application of optimizing mode 2 based on cost" and "hash-execution of a hash join or a subquery," specify the following:
pd_additional_optimize_level=1,2

Operand rules

Identifiers and unsigned integers cannot be specified together.
Identifier specification
Enclose each SQL extension optimizing option in quotation marks (").
If you do not use the SQL extension optimizing option explained here, specify NONE. However, if both NONE and an identifier other than NONE are specified, the specification of NONE is invalid.
Identifiers can be specified in uppercase or lowercase letters.
Specifying the same identifier more than once is the same as specifying it once.
Unsigned integer specification
If you do not use the SQL extension optimizing option explained here, specify 0. However, if both 0 and a non-zero unsigned integer are specified, the specification of 0 is invalid.
Specifying the same unsigned integer more than once is the same as specifying it once.

Specification guidelines: For specification guidelines, see SQL extension optimization option in the HiRDB Version 8 UAP Development Guide.

Notes

If the SQL optimization is specified in an SQL statement, SQL optimization specification takes precedence over the specification in this operand. For details on SQL optimization specification, see the HiRDB Version 8 SQL Reference.
If the SQL extension optimizing option is specified in an SQL statement (CREATE PROCEDURE, CREATE TYPE, CREATE TRIGGER, ALTER PROCEDURE, ALTER ROUTINE, or ALTER TRIGGER) inside a stored routine or trigger, the SQL extension optimizing option inside the SQL statement takes precedence over the specification in this operand.

Relationship to client environment definition: The value of this operand can be different for each client. To change the value for a client, specify the PDADDITIONALOPTLVL operand in the client environment definition. For details about the PDADDITIONALOPTLVL operand, see the HiRDB Version 8 UAP Development Guide.

5) pd_floatable_bes = "back-end-server-name"[,"back-end-server-name"]...

<identifier>((1-8 characters))

Specifies back-end servers to be used as floating servers.

Not all of the specified back-end servers may actually be used as floating servers.

Normally, servers used for data extraction are not used as floating servers. However, this operand enables servers that are used for data extraction to also become floating server candidates.

Operand rules

If an undefined back-end server name is specified, it is ignored.
If all the specified back-end server names are undefined, this entire operand is ignored.

Relationship to other operands

If the pd_non_floatable_bes operand is also specified, it is invalidated.
If the pd_floatable_bes operand is specified, "increasing the target floatable servers (back-end servers for fetching data)" of the pd_optimize_level operand is not applied.
If the pd_floatable_bes operand is specified, "limiting the target floatable servers (back-end servers for fetching data)" of the pd_optimize_level operand is not applied.

6) pd_non_floatable_bes = "back-end-server-name"[,"back-end-server-name"]...

<identifier>((1-8 characters))

Specifies back-end servers that are not to be used as floating servers.

If all back-end servers are specified, this operand is invalid.

Operand rule: If an undefined back-end server name is specified, it is ignored.

Relationship to other operands

If the pd_floatable_bes operand is also specified, it is invalidated.
If the pd_non_floatable_bes operand is specified, "increasing the target floatable servers (back-end servers for fetching data)" of the pd_optimize_level operand is not applied.
If the pd_non_floatable_bes operand is specified, "limiting the target floatable servers (back-end servers for fetching data)" of the pd_optimize_level operand is not applied.

6.3.2 Operands related to SQL optimization