Release 1 (9.0.1)
Part Number A88879-01
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| Oracle9i Application Developer's Guide - Large Objects (LOBs) Release 1 (9.0.1) Part Number A88879-01 |
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Temporary LOBs, 29 of 29
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See:
"Use Case Model: Internal Temporary LOBs", for all basic operations of Internal Temporary LOBs. |
This procedure describes how to disable temporary LOB buffering.
You enable buffering when performing a small series of reads or writes. Once you have completed these tasks, you must disable buffering before you can continue with any other LOB operations.
See Chapter 3, "LOB Support in Different Programmatic Environments" for a list of available functions in each programmatic environment. Use the following syntax references for each programmatic environment:
Not applicable.
Examples are provided in the following programmatic environments:
sb4 lobBuffering (envhp, errhp, svchp, stmthp) OCIEnv *envhp; OCIError *errhp; OCISvcCtx *svchp; OCIStmt *stmthp; { OCILobLocator *tblob; ub4 amt; ub4 offset; sword retval; ub1 bufp[MAXBUFLEN]; ub4 buflen; /* Allocate the descriptor for the lob locator: */ (void) OCIDescriptorAlloc((dvoid *) envhp, (dvoid **) &tblob, (ub4)OCI_DTYPE_LOB, (size_t) 0, (dvoid **) 0); /* Select the BLOB: */ printf (" create a temporary Lob\n"); /* Create a temporary LOB: */ if(OCILobCreateTemporary(svchp,errhp, tblob, (ub2)0, SQLCS_IMPLICIT, OCI_TEMP_BLOB, OCI_ATTR_NOCACHE, OCI_DURATION_SESSION)) { (void) printf("FAILED: CreateTemporary() \n"); return -1; } /* Open the BLOB: */ if (OCILobOpen(svchp, errhp, (OCILobLocator *) tblob, OCI_LOB_READWRITE)) { printf( "OCILobOpen FAILED for temp LOB \n"); return -1; } /* Enable LOB Buffering: */ printf (" enable LOB buffering\n"); checkerr (errhp, OCILobEnableBuffering(svchp, errhp, tblob)); printf (" write data to LOB\n"); /* Write data into the LOB: */ amt = sizeof(bufp); buflen = sizeof(bufp); offset = 1; checkerr (errhp, OCILobWrite (svchp, errhp, tblob, &amt, offset, bufp, buflen, OCI_ONE_PIECE, (dvoid *)0, (sb4 (*)(dvoid*,dvoid*,ub4*,ub1 *))0, 0, SQLCS_IMPLICIT)); /* Flush the buffer: */ printf(" flush the LOB buffers\n"); checkerr (errhp, OCILobFlushBuffer(svchp, errhp, tblob, (ub4)OCI_LOB_BUFFER_FREE)); /* Disable Buffering: */ printf (" disable LOB buffering\n"); checkerr (errhp, OCILobDisableBuffering(svchp, errhp, tblob)); /* Subsequent LOB WRITEs will not use the LOB Buffering Subsystem */ /* Closing the BLOB is mandatory if you have opened it: */ checkerr (errhp, OCILobClose(svchp, errhp, tblob)); /* Free the temporary LOB now that we are done using it: */ if(OCILobFreeTemporary(svchp, errhp, tblob)) { printf("OCILobFreeTemporary FAILED \n"); return -1; } /* Free resources held by the locators: */ (void) OCIDescriptorFree((dvoid *) tblob, (ub4) OCI_DTYPE_LOB); return; }
This script is also located at $ORACLE_HOME/rdbms/demo/lobs/cobol/tdisable
IDENTIFICATION DIVISION. PROGRAM-ID. TEMP-LOB-BUFFERING. ENVIRONMENT DIVISION. DATA DIVISION. WORKING-STORAGE SECTION. 01 USERID PIC X(11) VALUES "SAMP/SAMP". 01 TEMP-BLOB SQL-BLOB. 01 BUFFER PIC X(80). 01 AMT PIC S9(9) COMP VALUE 10. 01 ORASLNRD PIC 9(4). EXEC SQL VAR BUFFER IS RAW(80) END-EXEC. EXEC SQL INCLUDE SQLCA END-EXEC. EXEC ORACLE OPTION (ORACA=YES) END-EXEC. EXEC SQL INCLUDE ORACA END-EXEC. PROCEDURE DIVISION. TEMP-LOB-BUFFERING. EXEC SQL WHENEVER SQLERROR DO PERFORM SQL-ERROR END-EXEC. EXEC SQL CONNECT :USERID END-EXEC. * Allocate and initialize the CLOB locators: EXEC SQL ALLOCATE :TEMP-BLOB END-EXEC. EXEC SQL LOB CREATE TEMPORARY :TEMP-BLOB END-EXEC. * Enable buffering for the temporary LOB: EXEC SQL LOB ENABLE BUFFERING :TEMP-BLOB END-EXEC. * Write some data to the temporary LOB here: MOVE '252525262626252525' TO BUFFER. EXEC SQL LOB WRITE ONE :AMT FROM :BUFFER INTO :TEMP-BLOB END-EXEC * Flush the buffered writes: EXEC SQL LOB FLUSH BUFFER :TEMP-BLOB FREE END-EXEC. * Disable buffering for the temporary LOB: EXEC SQL LOB DISABLE BUFFERING :TEMP-BLOB END-EXEC. EXEC SQL LOB FREE TEMPORARY :TEMP-BLOB END-EXEC. EXEC SQL FREE :TEMP-BLOB END-EXEC. STOP RUN. SQL-ERROR. EXEC SQL WHENEVER SQLERROR CONTINUE END-EXEC. MOVE ORASLNR TO ORASLNRD. DISPLAY " ". DISPLAY "ORACLE ERROR DETECTED ON LINE ", ORASLNRD, ":". DISPLAY " ". DISPLAY SQLERRMC. EXEC SQL ROLLBACK WORK RELEASE END-EXEC. STOP RUN.
This script is also located at $ORACLE_HOME/rdbms/demo/lobs/proc/tdisbuf
#include <oci.h> #include <stdio.h> #include <sqlca.h> void Sample_Error() { EXEC SQL WHENEVER SQLERROR CONTINUE; printf("%.*s\n", sqlca.sqlerrm.sqlerrml, sqlca.sqlerrm.sqlerrmc); EXEC SQL ROLLBACK WORK RELEASE; exit(1); } #define BufferLength 1024 void disableBufferingTempLOB_proc() { OCIClobLocator *Temp_loc; varchar Buffer[BufferLength]; int Amount = BufferLength; int multiple, Length = 0, Position = 1; EXEC SQL WHENEVER SQLERROR DO Sample_Error(); /* Allocate and Create the Temporary LOB: */ EXEC SQL ALLOCATE :Temp_loc; EXEC SQL LOB CREATE TEMPORARY :Temp_loc; /* Enable use of the LOB Buffering Subsystem: */ EXEC SQL LOB ENABLE BUFFERING :Temp_loc; memset((void *)Buffer.arr, 42, BufferLength); Buffer.len = BufferLength; for (multiple = 0; multiple < 7; multiple++) { /* Write Data to the Temporary LOB: */ EXEC SQL LOB WRITE ONE :Amount FROM :Buffer INTO :Temp_loc AT :Position; Position += BufferLength; } /* Flush the contents of the buffers and Free their resources: */ EXEC SQL LOB FLUSH BUFFER :Temp_loc FREE; /* Turn off use of the LOB Buffering Subsystem: */ EXEC SQL LOB DISABLE BUFFERING :Temp_loc; /* Write APPEND can only be done when Buffering is Disabled: */ EXEC SQL LOB WRITE APPEND ONE :Amount FROM :Buffer INTO :Temp_loc; EXEC SQL LOB DESCRIBE :Temp_loc GET LENGTH INTO :Length; printf("Wrote a total of %d characters\n", Length); /* Free the Temporary LOB: */ EXEC SQL LOB FREE TEMPORARY :Temp_loc; /* Release resources held by the Locator: */ EXEC SQL FREE :Temp_loc; } void main() { char *samp = "samp/samp"; EXEC SQL CONNECT :samp; disableBufferingTempLOB_proc(); EXEC SQL ROLLBACK WORK RELEASE; }
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