ISOPEN Function

This function checks to see if the LOB was already opened using the input locator. This subprogram is for internal and external LOBs.

Syntax

DBMS_LOB.ISOPEN (
   lob_loc IN BLOB) 
  RETURN INTEGER; 

DBMS_LOB.ISOPEN (
   lob_loc IN CLOB CHARACTER SET ANY_CS) 
  RETURN INTEGER; 

DBMS_LOB.ISOPEN (
   file_loc IN BFILE) 
  RETURN INTEGER; 

Pragmas

pragma restrict_references(ISOPEN, WNDS, RNDS, WNPS, RNPS); 

Parameters

Table 22-32 ISOPEN Function Parameters

Parameter	Description
lob_loc	LOB locator.
file_loc	File locator.

Usage Notes

For BFILES, openness is associated with the locator. If the input locator was never passed to OPEN, the BFILE is not considered to be opened by this locator. However, a different locator may have opened the BFILE. More than one OPEN can be performed on the same BFILE using different locators.

For internal LOBs, openness is associated with the LOB, not with the locator. If locator1 opened the LOB, then locator2 also sees the LOB as open. For internal LOBs, ISOPEN requires a round-trip, because it checks the state on the server to see if the LOB is indeed open.

For external LOBs (BFILEs), ISOPEN also requires a round-trip, because that's where the state is kept.