Gives the JDBC driver used to read data a hint as to the number of rows that should be fetched from the database when more rows are needed. If this number is too low, the number of network round trips needed to retrieve the data increases. If the fetch size is too large, you may encounter memory issues.

Syntax

/*+ FORCE_FETCHSIZE(n) */

Arguments

  • n: A numeric of type BIGINT which specifies the forced rowcount. This number should be greater than or equal to zero.

Examples

FORCE_FETCHSIZE used in SELECT

SELECT /*+ FORCE_FETCHSIZE(1000) */ id, name FROM table1;

FORCE_FETCHSIZE used in COMPARE

COMPARE /*+ FORCE_FETCHSIZE(1000) */ mysystem.myschema TO yoursystem.yourschema ;

FORCE_FETCHSIZE used in DATACOPY

DATACOPY /*+ FORCE_FETCHSIZE(1000) */ mysystem.myschema TO yoursystem.yourschema;

FORCE FETCHSIZE used after JOIN

SELECT a.id, b.name
  FROM table1 a
  JOIN /*+ FORCE_FETCHSIZE(1000) */ table2 b
    ON b.id = a.id ;

See Also