anchor.diff:  == Garbage Collection
   
   When a lob datafile for a column has reached a certain limit, defined by a CQD `LOB_GC_LIMIT_SIZE`, then a compaction is triggered automatically. +
  -The default GC Limit is 10GB and can be changed if needed. 
  +The default Garbage Collection (GC) Limit is 10GB and can be changed if needed. 
   
   The need for GC arises because when a delete operation or an update operation is performed, the old data black in the hdfs file will be left as unused. +
   In the case of update, the old data will be left as unused and the new data will be written into a new section, so all these “holes” in the LOB data file are needlessly occupying space. 
  
positive.code: --- SQL operation complete.
  ```
  
  [#get statement for lob tables]
  == Get Statement for LOB Tables
  
  The GET Statement for lob tables gives column specific information on any lob columns in a table. 
  
  [#syntax]
  === Syntax
  
  ```
  GET LOB STATS FOR TABLE table-name;
  SELECT * FROM TABLE(LOB STATS table-name);
  ```
  
  [#examples]
  === Examples
  
  Suppose the following tables have been created:
  
  ```
  >>CREATE TABLE tlob130gt (c1 INT NOT NULL, c2 BLOB, c3 CLOB, c4 BLOB, PRIMARY KEY (c1));
  
  --- SQL operation complete.
  
  >>CREATE TABLE tlob130gt2 (c1 INT NOT NULL, c2 BLOB, c3 CLOB, c4 BLOB STORAGE 'EXTERNAL', PRIMARY KEY (c1));
  
  --- SQL operation complete.
  ```
  
  * This Get Statement displays statistics for the table tlob130gt, the lob information is formatted for machine readability.
  
  +
  
  ```
  >>SELECT left(trim(catalog_name) || '.' || trim(schema_name) || '.' || trim(object_name) , 20), left(trim(column_name),5), left(trim(lob_location),5) , left(trim(lob_data_file),20),LOB_DATA_FILE_SIZE_EOD,LOB_DATA_FILE_SIZE_USED from table(lob stats(tlob130gt));
  
  (EXPR)      (EXPR)     (EXPR)     (EXPR)     LOB_DATA_FILE_SIZE_EOD    LOB_DATA_FILE_SIZE_USED
  ------      ------     ------     ------     ----------------------    ----------------------
  
  TRAFODION.SCH.TLOB13   C2   /user/trafodion/lobs   LOBP_044744252290302   15   10
  TRAFODION.SCH.TLOB13   C3   /user/trafodion/lobs   LOBP_044744252290302   15   10
  TRAFODION.SCH.TLOB13   C4   /user/trafodion/lobs   LOBP_044744252290302   45   30
  
  --- 3 row(s) selected.
  ```
  
  
  * This Get Statement displays statistics for the table tlob130gt2, the lob information is formatted for human readability.
  
  +
  
  ```
  >>GET LOB STATS FOR TABLE tlob130gt2;
  
  Lob Information for table: "TRAFODION".LOB130.TLOB130GT2
  
negative.code: LOB Data File:  External HDFS File
  LOB EOD:  0
  LOB Used Len:  0
  --- SQL operation complete.
  ```
  
  [#select statment]
  === Select Statement
  
  [#syntax]
  ==== Syntax
  
  ```
  SELECT * FROM TABLE(LOB STATS table-name);
  ```
  
  [#examples]
  ==== Examples
  
  * This Select Statement displays statistics for the table tlob130gt.
  
  +
  
  ```
  >>CREATE TABLE tlob130gt (c1 INT NOT NULL, c2 BLOB, c3 CLOB, c4 BLOB, PRIMARY KEY (c1));
  
  --- SQL operation complete.
  
  >>SELECT left(trim(catalog_name) || '.' || trim(schema_name) || '.' || trim(object_name) , 20), 
  left(trim(column_name),5), 
  left(trim(lob_location),5), 
  left(trim(lob_data_file),20),
  LOB_DATA_FILE_SIZE_EOD,
  LOB_DATA_FILE_SIZE_USED 
  FROM TABLE(lob stats(tlob130gt));
  
  (EXPR)      (EXPR)     (EXPR)     (EXPR)     LOB_DATA_FILE_SIZE_EOD    LOB_DATA_FILE_SIZE_USED
  ------      ------     ------     ------     ----------------------    ----------------------
  
  TRAFODION.SCH.TLOB13   C2   /user/trafodion/lobs   LOBP_044744252290302   15   10
  TRAFODION.SCH.TLOB13   C3   /user/trafodion/lobs   LOBP_044744252290302   15   10
  TRAFODION.SCH.TLOB13   C4   /user/trafodion/lobs   LOBP_044744252290302   45   30
  
  --- 3 row(s) selected.
  ```
  
  * This Select Statement displays statistics for the table tlob130gt2.
  
  +
  
  ```
  >>CREATE TABLE tlob130gt2 (c1 INT NOT NULL, c2 BLOB, c3 CLOB, c4 BLOB STORAGE 'EXTERNAL', PRIMARY KEY (c1));
  
  --- SQL operation complete.
  
  >>SELECT left(trim(catalog_name) || '.' || trim(schema_name) || '.' || trim(object_name), 20), 
  left(trim(column_name),5), 
  left(trim(lob_location),15), 
  left(trim(lob_data_file),20),
  LOB_DATA_FILE_SIZE_EOD,
  LOB_DATA_FILE_SIZE_USED 
  FROM TABLE(lob stats(tlob130gt2));
  
  (EXPR)      (EXPR)     (EXPR)     (EXPR)     LOB_DATA_FILE_SIZE_EOD    LOB_DATA_FILE_SIZE_USED
  ------      ------     ------     ------     ----------------------    ----------------------
  