Can one export directly to a tape drive? —————————————– One can use a tape device name instead of a normal file name. When using a device, one also needs to specify the VOLSIZE= parameter. Look at this example: exp userid/password file=/dev/rmt0 table=emp volsize=1.2G Note: The volume size is a number ending with a “m”, “k”,…
If one cannot afford to buy extra disk space one can run the export and compress utilities simultaneously. This will prevent the need to get enough space for both the export file AND the compressed export file. Eg: # Make a pipe mknod expdat.dmp p # or mkfifo pipe # Start compress sucking on the…
This example uses the Unix split command to create multiple files, each smaller than the Unix (and imp/exp) 2 Gigabyte file size limit. This method can typically be used for import, export and SQL*Loader operations. cd /tmp/data rm exp.dmp mknod exp.dmp p # mkfifo on certain Unix flavours split -b2047m /tmp/data/exp.dmp & imp scott/tiger file=/tmp/data/exp.dmp…
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One can select a value from a database column directly into a Unix environment variable. Look at the following shell script examples: #!/bin/sh VALUE=`sqlplus -silent user/password@instance
Metalink Performance Library Index
BENEFITS of Locally Managed Tablespaces ————————————— Locally managed tablespaces track all extent information in the tablespace itself, using bitmaps, resulting in the following benefits: * Improved concurrency and speed of space operations, because space allocations and deallocations predominantly modify locally managed resources (bitmaps stored in header files) rather than requiring centrally managed resources such as…
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True Session Wait Activity in Oracle 10g ======================================== Catching a session waiting on a resource used to be hit or miss. Let’s take a look at how Oracle has helped give us a better mousetrap for seeing the waits experienced by sessions. It used to be that a DBA would sit in front of the…
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Interpreting Wait Event “file#” and “block#” parameters ======================================================= This reference note describes how to interpret file# and block# parameters from wait events (eg: obtained from or from the WAIT trace lines in trace files). The text uses: &AFN to represent the absolute file number (file#) &BLOCKNO to represent the block number (block#) IMPORTANT: The details…
wait.sql enqueue_type.sql lck.sql
select c.sid, c.serial#, c.username, a.object_id, b.object_name, c.program, c.status, d.name, c.osuser, e.sql_text, DBMS_ROWID.ROWID_CREATE(1, c.ROW_WAIT_OBJ#, c.ROW_WAIT_FILE#, c.ROW_WAIT_BLOCK#, c.ROW_WAIT_ROW# ) locked_rowid from v$Locked_object a, All_objects b, v$session c, audit_actions d, v$sqlarea e where a.object_id=b.object_id and a.session_id =c.sid(+) and c.command=d.action and c.row_wait_obj# != -1 and c.sql_id=e.sql_id;
