11.1.3 Bind Variable Peeking → good initial join order is a difficult problem. 11.1.3 Bind Variable Peeking In bind variable peeking … (also known as bind peeking ), the optimizer looks at the value in a bind variable when the database … . By peeking at bind values
OPTIMIZER_FEATURES_ENABLE → Peeking into user-defined bind variables X X X Index joins X X X Table 1-4 Optimizer Features for Oracle … X Complex view merging X X X X X X Peeking into user-defined bind variables X X X X X X Index joins … Optimizer Features for Oracle Database 11g Releases Features 220.127.116.11 Enhanced Bind Peeking
7.3.10 Sharing Cursors for Existing Applications → contained a bind variable and uses bind peeking to estimate cardinality. Statements that differ … statements use literals rather than bind variables, a nondefault setting for CURSOR_SHARING enables … the database to replace literals with system-generated bind variables. Using this technique, the
11.1 Overview of the Query Optimizer → statement. This section contains the following topics: Optimizer Operations Components of the Query Optimizer Bind Variable Peeking
Size Requirements for Bind Arrays → The bind array must be large enough to contain a single row. If the maximum row length exceeds the … size of the bind array, as specified by the BINDSIZE parameter, then SQL*Loader generates an error … . Otherwise, the bind array contains as many rows as can fit within it, up to the limit set by the … .) Although the entire bind
Cursor Sharing and Bind Variables → Bind Variables Query rewrite is supported when the query contains user bind variables as long as the … actual bind values are not required during query rewrite. If the actual values of the bind … variables are required during query rewrite, then we say that query rewrite is dependent on the bind values
Performance Implications of Bind Arrays → Large bind arrays minimize the number of calls to the Oracle database and maximize performance. In … general, you gain large improvements in performance with each increase in the bind array size up to … 100 rows. Increasing the bind array size to be greater than 100 rows generally delivers more modest
Bind Descriptors → data buffer addressed by BNDV(J). Often, bind-variable values are stored in character strings, so … Jth select-list or bind-variable value, reset SELT(J) or BNDT(J) to the datatype you want.
Bind Descriptors → DESCRIPTOR BND the buffer addressed by BNDI(J) determines whether the Jth bind variable is a . If the … elements of BNDI address elements of a data buffer array named BNDIV, and the value of BNDIV(J) is -1, the value of the Jth bind variable is set to NULL.
Bind Considerations → applications should not try to explicitly bind the REF CURSOR parameter to OracleCommand. ODP.NET
Bind Descriptors → bind-variable values addressed by BNDV(1) through BNDV(BNDN). If the elements of BNDV address elements … of a data buffer array named BNDVB, Oracle finds the Jth bind-variable value in data buffer BNDVB(J).
bind variable → A variable in a SQL statement that must be replaced with a valid value, or the address of a value, in order for the statement to successfully execute.
Bind Descriptors → in that buffer. If you want to change the length Oracle uses for the Jth select-list or bind
Bind Arrays and Conventional Path Loads → read at one time and stored in the bind array. When SQL*Loader sends the Oracle database an INSERT … command, the entire array is inserted at one time. After the rows in the bind array are inserted, a … COMMIT statement is issued. The determination of bind array size pertains to SQL*Loader's
Calculations to Determine Bind Array Size → The bind array's size is equivalent to the number of rows it contains times the maximum length of … follows: bind array size = (number of rows) * ( SUM(fixed field lengths) + SUM(maximum varying field … storage that each field occupies in the bind array, but the bind array includes additional overhead for … fields
Minimizing Memory Requirements for Bind Arrays → —especially when multiplied by the number of rows in the bind array. It is best to specify the smallest … \",\" With byte-length semantics, this example uses (10 + 2) * 64 = 768 bytes in the bind array, assuming … -length semantics, the same example uses ((10 * s) + 2) * 64 bytes in the bind array, where \"s\" is the … a delimited
Calculating Bind Array Size for Multiple INTO TABLE Clauses → When calculating a bind array size for a control file that has multiple INTO TABLE clauses … file as one, long data structure—that is, the format of a single row in the bind array. If the same … bind array is required each time it is mentioned. It is especially important to minimize the buffer … , EXPRESSION, RECNUM, SYSDATE,
Specifying Number of Rows Versus Size of Bind Array → When you specify a bind array size using the command-line parameter BINDSIZE or the OPTIONS clause … in the control file, you impose an upper limit on the bind array. The bind array never exceeds that … . If that size fits within the bind array maximum, then the load continues—SQL*Loader does not try to … expand
DESCRIBE the Bind Variables → DESCRIBE BIND VARIABLES puts descriptions of placeholders into a bind descriptor. In our example … , DESCRIBE readies bind_des, as follows: EXEC SQL DESCRIBE BIND VARIABLES FOR sql_stmt INTO bind_des … ; Note that bind_des must not be prefixed with a colon. The DESCRIBE BIND VARIABLES statement must … follow the
Bind and Define Examples → The examples in this section demonstrate how you can use variables of type OCINumber in OCI bind … placeholder:newsal, specifying an external data type of VARNUM (data type code=6) in the bind