Don’t know how your tables are growing or shrinking over time then this article should help you, and it uses built in DB2 administrative view called SYSIBMADM.ADMINTABINFO so nothing too complicated to do here; full details about SYSIBMADM.ADMINTABINFO can be found in the IBM Help Centre.
Below I will go through the DB2 objects that I have created to record this info and how you can implement this yourself.
The view using SYSIBMADM.ADMINTABINFO
So that I have something I can query during the day after I have added quantities of data or I can use it in an stored procedure to record the daily table sizes:
CREATE VIEW DB_MAIN.TABLE_SIZES AS (
SELECT CURRENT_DATE AS STATS_DATE,
TABNAME AS TABNAME,TABSCHEMA AS TABSCHEMA,TABTYPE AS TABTYPE,TOTAL_SIZE AS TOTAL_OBJECT_P_SIZE,DATA_SIZE AS DATA_OBJECT_P_SIZE,DICT_SIZE AS DICTIONARY_SIZE,INDEX_SIZE AS INDEX_OBJECT_P_SIZE,LOB_SIZE AS LOB_OBJECT_P_SIZE,LONG_SIZE AS LONG_OBJECT_P_SIZE,XML_SIZE AS XML_OBJECT_P_SIZE FROM table(SELECT
TABNAME,
TABSCHEMA,
TABTYPE,
DECIMAL(((data_object_p_size + index_object_p_size + long_object_p_size + lob_object_p_size + xml_object_p_size)/ 1024.0),10,3) as total_size,
DECIMAL((DATA_OBJECT_P_SIZE / 1024.0),10,3) AS DATA_SIZE,
DECIMAL((DICTIONARY_SIZE / 1024.0),10,2) AS DICT_SIZE,
DECIMAL((INDEX_OBJECT_P_SIZE / 1024.0),10,3) AS INDEX_SIZE,
DECIMAL((LOB_OBJECT_P_SIZE / 1024.0),10,3) AS LOB_SIZE,
DECIMAL((LONG_OBJECT_P_SIZE / 1024.0),10,3) AS LONG_SIZE, DECIMAL((XML_OBJECT_P_SIZE / 1024.0),10,3) AS XML_SIZE
FROM SYSIBMADM.ADMINTABINFO WHERE TABSCHEMA NOT LIKE 'SYS%'
AND TABSCHEMA NOT LIKE 'SNAP%') as TABLESIZE
)
The view is not all the columns that are available in the view but are the ones that are the most useful for general day to day usage, there are many more here that you could use. The values are stored in Kb’s so need dividing by 1024 to get it too Mb’s. The other GOTCHA is that partitioned tables will appear as one row per partition.
Table sizes record table
Rubbish section title I know but have tried several different names. This is the meta table that will record the information from the cut down version of the view from the stored procedure below.
CREATE TABLE DB_MAIN.TABLE_SIZES_STATS (
STATS_DATE DATE NOT NULL,
TABNAME VARCHAR(128),
TABSCHEMA VARCHAR(128),
TABTYPE CHARACTER(1),
TOTAL_OBJECT_P_SIZE DECIMAL(10,3),
DATA_OBJECT_P_SIZE DECIMAL(10,3),
DICTIONARY_SIZE DECIMAL(10,2),
INDEX_OBJECT_P_SIZE DECIMAL(10,3),
LOB_OBJECT_P_SIZE DECIMAL(10,3),
LONG_OBJECT_P_SIZE DECIMAL(10,3),
XML_OBJECT_P_SIZE DECIMAL(10,3)
)
IN DB_MAIN_TS
COMPRESS YES
Please note that if you do not have the “Storage Optimisation Feature” from IBM then please do not include the line “COMPRESS YES”, otherwise if the big blue comes to do an audit you could be in trouble. The best thing to avoid this is set the licensing to hard
Stored procedure for recording table sizes using SYSIBMADM.ADMINTABINFO
This is the stored procedure that I use to stored the size of the at the time of running the SP.
CREATE PROCEDURE DB_MAIN.ADD_TABLE_SIZES_STATS ()
LANGUAGE SQL
BEGIN
INSERT INTO DB_MAIN.TABLE_SIZES_STATS
SELECT *
FROM DB_MAIN.TABLE_SIZES
WITH UR;
END
What to do next
As stated earlier then you can use this to record the day to day table sizes, or if you are in the process of compressing your tables you can use this to record the sizes before and after. In a future article then I will be using this object created here to show how much table size has decreased in implementing adaptive compression.