Listing Objects in an Oracle Tablespace
SQL lists all objects within a specific tablespace in an Oracle database
A detailed explanation of Oracle Database SQL code used to list objects within a tablespace, including purpose, breakdown, key points, and insights.
Sample SQL Command
1set pages 999
2col owner format a15
3col segment_name format a40
4col segment_type format a20
5select owner
6, segment_name
7, segment_type
8from dba_segments
9where lower(tablespace_name) like lower('%&tablespace%')
10order by owner, segment_name
11/
Sample Oracle Output:
1OWNER SEGMENT_NAME SEGMENT_TYPE
2--------------- ---------------------------------------- --------------------
3LARRY BIN$Q+k4qsgBLNngRAAQg5ZRWg==$0 INDEX
4LARRY BIN$Q+k4qsgCLNngRAAQg5ZRWg==$0 TABLE
5LARRY BIN$Q+k4qsgELNngRAAQg5ZRWg==$0 INDEX
6LARRY BIN$Q+k4qsgFLNngRAAQg5ZRWg==$0 TABLE
7LARRY BOX TABLE
8LARRY BOX_PK INDEX
9LARRY CD TABLE
10LARRY CD_PK INDEX
11LARRY LOCATION TABLE
12LARRY LOCATION_PK INDEX
13LARRY LOTS_OF_ROWS TABLE
14LARRY POO TABLE
15LARRY SERVERS TABLE
16LARRY SYS_C0023466 INDEX
17LARRY SYS_C0023467 INDEX
18LARRY SYS_C0027234 INDEX
19LARRY TEST_TABLE TABLE
20LARRY TRACK TABLE
21LARRY TRACK_PK INDEX
22
2319 rows selected.
Purpose:
- To identify and display all database objects (like tables, indexes, partitions) residing in a chosen tablespace.
Breakdown:
set pages 999
: This setting increases the number of rows displayed per page to 999. This might be necessary if the tablespace holds a large number of objects.col owner format a15
,col segment_name format a40
**,col segment_type format a20
**: These lines define column formatting in the output. They set specific widths for the "owner", "segment_name", and "segment_type" columns to improve readability.select owner, segment_name, segment_type
: This clause selects three specific columns from thedba_segments
system view:owner
: The schema (user) who owns the object.segment_name
: The actual name of the object.segment_type
: The type of object (TABLE, INDEX, PARTITION, etc.).
from dba_segments
: This specifies the data source for the query.dba_segments
holds information about all database segments, including their type, owner, and tablespace association.where lower(tablespace_name) like lower('%&tablespace%')
: This clause filters the results based on the tablespace name.lower(tablespace_name)
: Converts the tablespace name to lowercase for case-insensitive comparison.like lower('%&tablespace%')
: Uses a wildcard comparison with%
to accept any tablespace name passed as the&tablespace
variable.
order by owner, segment_name
: This clause sorts the output first by owner and then by segment name within each owner.
Key Points:
- This code relies on the
dba_segments
system view, which requires appropriate privileges to access (typically DBA or SYSDBA). - The
like
clause with wildcards allows for listing objects in any tablespace whose name matches the provided part. - The code filters for all object types (
segment_type
). If you only need specific types (e.g., tables), modify thewhere
clause accordingly. - Consider additional filtering using other columns from
dba_segments
for more granular results.
Insights and Explanations:
- Setting a large page size with
set pages
might not be needed in all cases and could impact performance for very large tablespaces. Adjust as needed. - Using wildcards in the
where
clause offers flexibility but introduces security risks if not controlled properly. Ensure the&tablespace
variable is validated and sanitized before execution. - The code provides a basic listing of objects. Extending it to include additional information (e.g., object creation date, size) can be achieved by incorporating more columns from
dba_segments
.
This code snippet effectively fulfills its purpose of listing all objects within a specified tablespace, but remember to exercise caution and adapt it to your specific needs and security requirements.