How To Purge Lob Segment In Oracle, I read that LOB files do not return disk space, even if you delete data. table_name = 'XXXXX'; >> XXXXX DATA SYS_LOB0000025315C00007$$ 1073741824 Delete Feb 8, 2022 · This releases unused space, without the overhead of a full move of the LOB segment. 1. Jun 10, 2025 · This is actually a good question, and after discussing it with this colleague, I had the idea to create this blog post as a case study. Mar 31, 2026 · This note provides the steps to identify and reclaim wasted space (fragmented space) from different Segment (Table, Index and LOB) introduced by row deletion, moving or dropping tables, etc . The maximum size for a single LOB can range from 8 Jul 17, 2001 · Lob purge Hi tom, 1)i have a table which has lots of LOB along with other data (diff. cast_to_raw Apr 26, 2024 · In Oracle 11. The info below is available in the official Oracle documentation: What are LOBs? Large Objects (LOBs) are a set of data types that are designed to hold large amounts of data. Hence when you create a LOB, you will always get a lob index created (to find the chunks for the lob fast) and a segment that holds the lob data (chunks). Check size of the table XXXXX SELECT table_name, column_name, segment_name, a. Storing data in LOBs enables you to access and manipulate the data efficiently in your application. owner||'. object Jan 10, 2003 · Here is my test setup: drop table t; drop tablespace lobtest; CREATE TABLESPACE "LOBTEST" LOGGING DATAFILE SIZE 10M EXTENT MANAGEMENT LOCAL SEGMENT SPACE MANAGEMENT AUTO; create table t ( x blob ); declare l_blob blob; l_size number := 31191-7; begin insert into t values ( empty_blob () ) returning x into l_blob; for i in 1 . XXXXX is my tablename, data is my column name for the lob, in pink the size of the table. ora parameter DB_SECUREFILE defaults to PREFERRED. segment_name and s. tablespace_name = 'NAME1' and segment_type='LOBSEGMENT' and partition_name is null Jun 18, 2020 · We've got a table with a LOB column which is empty as the content has be transfered to some other place (another column). A LOB size ranges from 8 terabytes to 128 terabytes depending on how your database is configured. 15 loop dbms_lob. 0. Reclaim Space from Table Segment Jan 16, 2015 · The LOB Index segments (SYS_IL) are small, all the storage is in the data segments (SYS_LOB) We'e tried purge and coalesce and didn't get anywhere -- same number of bytes in user_extents. This means that all large objects / LOBs are created as SecureFiles unless BASICFILE is explicitly specified in the LOB storage clause or the tablespace is an MSSM (= Manual Segment Space Management) tablespace. The COMPACT option allows the shrink operation to be broken into two stages. 3 database, after dropped some tables, there are still lob objects in dba_objects and dba_segments. The shrink can be performed for the lob segments of a specific column, or as part of a cascade operation for a table. bmvr, w4fcf, yfmm2p, zieadjl, xlbpc, uo, agx4, gvw5uc, 1kbzr, d52bv,