Background
Currently I am using DB2 V9 version. One of my stored procedure is taking time to execute. I looked BMC apptune and found the following SQL.
There are three tables we were using to execute the following query.
ACCOUNT table is having 3413 records
EXCHANGE_RATE is having 1267K records
BALANCE is having 113M records
Someone has added recently following piece of code in the query. I think because of this we had a problem.
AND (((A.ACT <> A.EW_ACT)
AND (A.EW_ACT <> ' ')
AND (C.ACT = A.EW_ACT))
OR (C.ACT = A.ACT))
Query
SELECT F1.CLO_LED
INTO :H :H
FROM (SELECT A.ACT, A.BNK, A.ACT_TYPE,
CASE WHEN :H = A.CUY_TYPE THEN DEC(C.CLO_LED, 21, 2)
ELSE DEC(MULTIPLY_ALT(C.CLO_LED, COALESCE(B.EXC_RATE, 0)), 21, 2)
END AS CLO_LED
FROM ACCOUNT A
LEFT OUTER JOIN EXCHANGE_RATE B
ON B.EFF_DATE = CURRENT DATE - 1 DAY
AND B.CURCY_FROM = A.CURNCY_TYPE
AND B.CURCY_TO = :H
AND B.STA_TYPE = 'A'
, BALANCE C
WHERE A.CUSR_ID = :DCL.CUST-ID
AND A.ACT = :DCL.ACT
AND A.EIG_RTN = :WS-BNK-ID
AND A.ACT_TYPE = :DCL.ACT-TYPE
AND A.ACT_CAT = :DCL.ACT-CAT
AND A.STA_TYPE = 'A'
AND (((A.ACT <> A.EW_ACT)
AND (A.EW_ACT <> ' ')
AND (C.ACT = A.EW_ACT))
OR (C.ACT = A.ACT))
AND C.BNK = :WS-BNK-ID
AND C.ACT_TYPE = :DCL.ACT-TYPE
AND C.BUS_DATE = :WS-DATE-FROM) F1
WITH UR
There's a number of wierd things going on in this query. The most twitchy of which is mixing explicit joins with the implicit-join syntax; frankly, I'm not certain how the system interprets it. You also appear to be using the same host-variable for both input and output; please don't.
Also, why are your column names so short? DB2 (that version, at least) supports column names that are much longer. Please save people's sanity, if at all possible.
We can't completely say why things are slow - we may need to see access plans. In the meantime, here's your query, restructured to what may be a faster form:
SELECT CASE WHEN :inputType = a.cuy_type THEN DEC(b.clo_led, 21, 2)
ELSE DEC(MULTIPLY_ALT(b.clo_led, COALESCE(c.exc_rate, 0)), 21, 2) END
INTO :amount :amountIndicator -- if you get results, do you need the indiciator?
FROM Account as a
JOIN Balance as b -- This is assumed to not be a 'left', given coalesce not used
ON b.bnk = a.eig_rtn
AND b.act_type = a.act_type
AND b.bus_date = :ws-date-from
AND ((a.act <> a.ew_act -- something feels wrong here, but
AND a.ew_act <> ' ' -- without knowing the data, I don't
AND c.act = a.ew_act) -- want to muck with it.
OR c.act = a.act)
LEFT JOIN Exchange_Rate as c
ON c.eff_date = current_date - 1 day
AND c.curcy_from = a.curncy_type
AND c.sta_type = a.sta_type
AND c.curcy_to = :destinationCurrency
WHERE a.cusr_id = :dcl.cust-id
AND a.act = :dcl.act
AND a.eig_rtn = :ws-bnk-id
AND a.act_type = :dcl.act-type
AND a.act_cat = :dcl.act-cat
AND a.sta_type = 'A'
WITH UR
FECTCH FIRST 1 ROW ONLY
A few other notes:
Only specify exactly those columns needed - under certain circumstances, this permits index-only access, where otherwise a followup table-access may be needed. However, this probably won't help here.
COALESCE(c.exc_rate, 0) feels off somehow - if no exchange rate is present, you return an amount of 0, which could otherwise be a valid amount. You may need to return some sort of indicator, or make it a normal join, not an outer one.
Also, try both this version, and possibly a version where host variables are specified in addition to the conditions between tables. The optimizer should be able to automatically commute the values, but may not under some conditions (implementation detail).
Related
I'm working in a bank so I had to adjust the column names and information in the query to fit the external web, so if there're any weird mistakes know it is somewhat fine.
I'm trying to use the CASE clause to display data from a different table, I know this is a workaround but due to certain circumstances I'm obligated to use it, plus it is becoming interesting to figure out if there's an actual solution.
The error I'm receiving for the following query is:
"ERROR [21000] [IBM][CLI Driver][DB2] SQL0811N The result of a scalar
fullselect, SELECT INTO statement, or VALUES INTO statement is more
than one row."
select bank_num, branch_num, account_num, client_id,
CASE
WHEN exists(
select *
from bank.services BS
where ACCS.client_id= BS.sifrur_lakoach
)
THEN (select username from bank.services BS where BS.client_id = ACCS.client_id)
ELSE 'NONE'
END username_new
from bank.accounts accs
where bank_num = 431 and branch_num = 170
EDIT:
AFAIK we're using DB2 v9.7:
DSN11015 - DB21085I Instance "DB2" uses "64" bits and DB2 code release "SQL09075" with
level identifier "08060107".
Informational tokens are "DB2 v9.7.500.702", "s111017", "IP23287", and Fix Pack "5".
Use listagg function to include all results.
select bank_num, branch_num, account_num, client_id,
CASE
WHEN exists(
select *
from bank.services BS
where ACCS.client_id= BS.sifrur_lakoach
)
THEN (select LISTAGG(username, ', ') from bank.services BS
where BS.client_id = ACCS.client_id)
ELSE 'NONE'
END username_new
from bank.accounts accs
where bank_num = 431 and branch_num = 170
I have the following select statement in ABAP:
SELECT munic~mandt VREFER BIS AB ZZELECDATE ZZCERTDATE CONSYEAR ZDIMO ZZONE_M ZZONE_T USAGE_M USAGE_T M2MC M2MT M2RET EXEMPTMCMT EXEMPRET CHARGEMCMT
INTO corresponding fields of table GT_INSTMUNIC_F
FROM ZCI00_INSTMUNIC AS MUNIC
INNER JOIN EVER AS EV on
MUNIC~POD = EV~VREFER(9).
"where EV~BSTATUS = '14' or EV~BSTATUS = '32'.
My problem with the above statement is that does not recognize the substring/offset operation on the 'ON' clause. If i remove the '(9) then
it recognizes the field, otherwise it gives error:
Field ev~refer is unknown. It is neither in one of the specified tables
nor defined by a "DATA" statement. I have also tried doing something similar in the 'Where' clause, receiving a similar error:
LOOP AT gt_instmunic.
clear wa_gt_instmunic_f.
wa_gt_instmunic_f-mandt = gt_instmunic-mandt.
wa_gt_instmunic_f-bis = gt_instmunic-bis.
wa_gt_instmunic_f-ab = gt_instmunic-ab.
wa_gt_instmunic_f-zzelecdate = gt_instmunic-zzelecdate.
wa_gt_instmunic_f-ZZCERTDATE = gt_instmunic-ZZCERTDATE.
wa_gt_instmunic_f-CONSYEAR = gt_instmunic-CONSYEAR.
wa_gt_instmunic_f-ZDIMO = gt_instmunic-ZDIMO.
wa_gt_instmunic_f-ZZONE_M = gt_instmunic-ZZONE_M.
wa_gt_instmunic_f-ZZONE_T = gt_instmunic-ZZONE_T.
wa_gt_instmunic_f-USAGE_M = gt_instmunic-USAGE_M.
wa_gt_instmunic_f-USAGE_T = gt_instmunic-USAGE_T.
temp_pod = gt_instmunic-pod.
SELECT vrefer
FROM ever
INTO wa_gt_instmunic_f-vrefer
WHERE ( vrefer(9) LIKE temp_pod ). " PROBLEM WITH SUBSTRING
"AND ( BSTATUS = '14' OR BSTATUS = '32' ).
ENDSELECT.
WRITE: / sy-dbcnt.
WRITE: / 'wa is: ', wa_gt_instmunic_f.
WRITE: / 'wa-ever is: ', wa_gt_instmunic_f-vrefer.
APPEND wa_gt_instmunic_f TO gt_instmunic_f.
WRITE: / wa_gt_instmunic_f-vrefer.
ENDLOOP.
itab_size = lines( gt_instmunic_f ).
WRITE: / 'Internal table populated with', itab_size, ' lines'.
The basic task i want to implement is to modify a specific field on one table,
pulling values from another. They have a common field ( pod = vrefer(9) ). Thanks in advance for your time.
If you are on a late enough NetWeaver version, it works on 7.51, you can use the OpenSQL function LEFT or SUBSTRING. Your query would look something like:
SELECT munic~mandt VREFER BIS AB ZZELECDATE ZZCERTDATE CONSYEAR ZDIMO ZZONE_M ZZONE_T USAGE_M USAGE_T M2MC M2MT M2RET EXEMPTMCMT EXEMPRET CHARGEMCMT
FROM ZCI00_INSTMUNIC AS MUNIC
INNER JOIN ever AS ev
ON MUNIC~POD EQ LEFT( EV~VREFER, 9 )
INTO corresponding fields of table GT_INSTMUNIC_F.
Note that the INTO clause needs to move to the end of the command as well.
field(9) is a subset operation that is processed by the ABAP environment and can not be translated into a database-level SQL statement (at least not at the moment, but I'd be surprised if it ever will be). Your best bet is either to select the datasets separately and merge them manually (if both are approximately equally large) or pre-select one and use a FAE/IN clause.
They have a common field ( pod = vrefer(9) )
This is a wrong assumption, because they both are not fields, but a field an other thing.
If you really need to do that task through SQL, I'll suggest you to check native SQL sentences like SUBSTRING and check if you can manage to use them within an EXEC_SQL or (better) the CL_SQL* classes.
I have written below SQL in an RPGLE program. Intent is to update the header file (TC400F) if no corresponding records exist in detail file (TC401F). Are there better ways of doing this? By better, I mean that would make the query run faster or would make it look more cleaner.
Exec SQL UPDATE TC400F
SET T40STS = '05',
T40OFL = '1'
WHERE T40SID = :K#T41SID AND
T40PID = :K#T41PID AND
NOT EXISTS (SELECT * FROM TC401F WHERE
T41SID = :K#T41SID AND
T41PID = :K#T41PID );
try this :
Exec SQL UPDATE TC400F f1
SET (f1.T40STS, f1.T40OFL) = ('05', '1')
WHERE f1.T40SID = :K#T41SID AND
f1.T40PID = :K#T41PID AND
NOT EXISTS
(
SELECT * FROM TC401F f2
WHERE (f1.T41SID, f1.T41PID) = (f2.T41SID, f2.T41PID)
);
You have not done anything here that explicitly restricts performance. The optimizer is pretty smart these days. Most of the things that affect SQL performance are external to the statement. Best to write the statement to be semantically correct (as you have above), and let the optimizer do it's thing. Then if you see performance issues, then investigate them with then Explain tools in Run SQL Scripts. Most likely your performance issues will derive from incorrect indexes.
Exec SQL UPDATE TC400F
SET T40STS = '05',
T40OFL = '1'
WHERE (t40sts <> '05' or t40ofl <> '1')
and T40SID = :K#T41SID
AND T40PID = :K#T41PID
and
NOT EXISTS (SELECT onefieldhere FROM TC401F WHERE
T41SID = :K#T41SID AND
T41PID = :K#T41PID );
Add a little optimistic code don't update what is already set.
Please don't make the as400 an orphan by ending a line with an operator that is the start of the next line. Optimistic updates are probably fastest when values are already set because it knows its already done. You could make it better by using the alias field names so someone in the future will know what a t40ofl is. Select only one field from the exists clause so sql won't have to pull in a whole row.
I have a query:
SELECT DISTINCT ON (analytics_staging_v2s.event_type, sent_email_v2s.recipient, sent_email_v2s.sent) sent_email_v2s.id, sent_email_v2s.user_id, analytics_staging_v2s.event_type, sent_email_v2s.campaign_id, sent_email_v2s.recipient, sent_email_v2s.sent, sent_email_v2s.stage, sent_email_v2s.sequence_id, people.role, people.company, people.first_name, people.last_name, sequences.name as sequence_name
FROM "sent_email_v2s"
LEFT JOIN analytics_staging_v2s ON sent_email_v2s.id = analytics_staging_v2s.sent_email_v2_id
JOIN people ON sent_email_v2s.person_id = people.id
JOIN sequences on sent_email_v2s.sequence_id = sequences.id
JOIN users ON sent_email_v2s.user_id = users.id
WHERE "sent_email_v2s"."status" = 1
AND "people"."person_type" = 0
AND (sent_email_v2s.sequence_id = 1888) AND (sent_email_v2s.sent >= '2016-03-18')
AND "users"."team_id" = 1
When I run EXPLAIN ANALYZE on it, I get:
Then, if I change that to the following (Just removing the (sent_email_v2s.sent >= '2016-03-18')) as follows:
SELECT DISTINCT ON (analytics_staging_v2s.event_type, sent_email_v2s.recipient, sent_email_v2s.sent) sent_email_v2s.id, sent_email_v2s.user_id, analytics_staging_v2s.event_type, sent_email_v2s.campaign_id, sent_email_v2s.recipient, sent_email_v2s.sent, sent_email_v2s.stage, sent_email_v2s.sequence_id, people.role, people.company, people.first_name, people.last_name, sequences.name as sequence_name
FROM "sent_email_v2s"
LEFT JOIN analytics_staging_v2s ON sent_email_v2s.id = analytics_staging_v2s.sent_email_v2_id
JOIN people ON sent_email_v2s.person_id = people.id
JOIN sequences on sent_email_v2s.sequence_id = sequences.id
JOIN users ON sent_email_v2s.user_id = users.id
WHERE "sent_email_v2s"."status" = 1
AND "people"."person_type" = 0
AND (sent_email_v2s.sequence_id = 1888) AND "users"."team_id" = 1
when I run EXPLAIN ANALYZE on this query, the results are:
EDIT:
The results above from today are about as I expected. When I ran this last night, however, the difference created by including the timestamp filter was about 100x slower (0.5s -> 59s). The EXPLAIN ANALYZE from last night showed all of the time increase to be attributed to the first unique/sort operation in the query plan above.
Could there be some kind of caching issue here? I am worried now that there might be something else going on (transiently) that might make this query take 100x longer since it happened at least once.
Any thoughts are appreciated!
I have a SQL 2008 R2 database with some tables on it having some of those tables a Full-Text Index defined. I'd like to know how to determine the size of the index of a specific table, in order to control and predict it's growth.
Is there a way of doing this?
The catalog view sys.fulltext_index_fragments keeps track of the size of each fragment, regardless of catalog, so you can take the SUM this way. This assumes the limitation of one full-text index per table is going to remain the case. The following query will get you the size of each full-text index in the database, again regardless of catalog, but you could use the WHERE clause if you only care about a specific table.
SELECT
[table] = OBJECT_SCHEMA_NAME(table_id) + '.' + OBJECT_NAME(table_id),
size_in_KB = CONVERT(DECIMAL(12,2), SUM(data_size/1024.0))
FROM sys.fulltext_index_fragments
-- WHERE table_id = OBJECT_ID('dbo.specific_table_name')
GROUP BY table_id;
Also note that if the count of fragments is high you might consider a reorganize.
If you are after a specific Catalogue
Use SSMS
- Clik on [Database] and expand the objects
- Click on [Storage]
- Right Click on {Specific Catalogue}
- Choose Propertie and click.
IN General TAB.. You will find the Catalogue Size = 'nn'
I use something similar to this (which will also calculate the size of XML-indexes, ... if present)
SELECT S.name,
SO.name,
SIT.internal_type_desc,
rows = CASE WHEN GROUPING(SIT.internal_type_desc) = 0 THEN SUM(SP.rows)
END,
TotalSpaceGB = SUM(SAU.total_pages) * 8 / 1048576.0,
UsedSpaceGB = SUM(SAU.used_pages) * 8 / 1048576.0,
UnusedSpaceGB = SUM(SAU.total_pages - SAU.used_pages) * 8 / 1048576.0,
TotalSpaceKB = SUM(SAU.total_pages) * 8,
UsedSpaceKB = SUM(SAU.used_pages) * 8,
UnusedSpaceKB = SUM(SAU.total_pages - SAU.used_pages) * 8
FROM sys.objects SO
INNER JOIN sys.schemas S ON S.schema_id = SO.schema_id
INNER JOIN sys.internal_tables SIT ON SIT.parent_object_id = SO.object_id
INNER JOIN sys.partitions SP ON SP.object_id = SIT.object_id
INNER JOIN sys.allocation_units SAU ON (SAU.type IN (1, 3)
AND SAU.container_id = SP.hobt_id)
OR (SAU.type = 2
AND SAU.container_id = SP.partition_id)
WHERE S.name = 'schema'
--AND SO.name IN ('TableName')
GROUP BY GROUPING SETS(
(S.name,
SO.name,
SIT.internal_type_desc),
(S.name, SO.name), (S.name), ())
ORDER BY S.name,
SO.name,
SIT.internal_type_desc;
This will generally give numbers higher than sys.fulltext_index_fragments, but when combined with the sys.partitions of the table, it will add up to the numbers returned from EXEC sys.sp_spaceused #objname = N'schema.TableName';.
Tested with SQL Server 2016, but documentation says it should be present since 2008.