Need to optimize Teradata query - query-optimization

Question

I am trying to optimize the following teradata query. Can anyone please on this. It is taking lot of time to retrieve records.
select top 100 I.item_sku_nbr,L.loc_nbr,MIS.MVNDR_PRTY_ID from
QA_US_MASTER_VIEWS.item I,
qa4_US_MASTER_VIEWS.location L,
qa4_US_MASTER_VIEWS.item_str IST,
qa4_US_MASTER_VIEWS.mvndr_item_str MIS
where MIS.str_LOC_ID = L.loc_id and
mis.str_loc_id = IST.str_loc_id and
IST.str_loc_id = L.loc_id and
MIS.ITEM_STAT_CD = IST.ITEM_STAT_CD and
IST.ITEM_ID = I.ITEM_ID and
MIS.ITEM_ID = IST.ITEM_ID and
I.ITEM_STAT_CD = 100 and
IST.curr_rmeth_cd = 2 and
MIS.curr_dsvc_typ_cd = 3 and
MIS.OK_TO_ORD_FLG = 'Y' and
MIS.EFF_END_DT = DATE '9999-12-31' and
IST.EFF_END_DT = DATE '9999-12-31' and
MIS.ACTV_FLG ='Y' and
IST.ACTV_FLG ='Y' and I.ACTV_FLG='Y'
Explain plan for QA_US_MASTER.LOCATION:
1) First, we lock QA_US_MASTER.LOCATION in view
qa4_US_MASTER_VIEWS.Location for access.
2) Next, we do an all-AMPs RETRIEVE step from QA_US_MASTER.LOCATION
in view qa4_US_MASTER_VIEWS.Location by way of an all-rows scan
with no residual conditions into Spool 1 (group_amps), which is
built locally on the AMPs. The size of Spool 1 is estimated with
high confidence to be 10,903 rows (1,613,644 bytes). The
estimated time for this step is 0.01 seconds.
3) Finally, we send out an END TRANSACTION step to all AMPs involved
in processing the request.
-> The contents of Spool 1 are sent back to the user as the result of
statement 1. The total estimated time is 0.01 seconds.
Explain plan for qa4_US_MASTER_VIEWS.item_str :
1) First, we lock QA_US_MASTER.item_str in view
qa4_US_MASTER_VIEWS.item_str for access.
2) Next, we do an all-AMPs RETRIEVE step from QA_US_MASTER.item_str
in view qa4_US_MASTER_VIEWS.item_str by way of an all-rows scan
with no residual conditions into Spool 1 (group_amps), which is
built locally on the AMPs. The input table will not be cached in
memory, but it is eligible for synchronized scanning. The result
spool file will not be cached in memory. The size of Spool 1 is
estimated with low confidence to be 1,229,047,917 rows (
325,697,698,005 bytes). The estimated time for this step is 4
minutes and 51 seconds.
3) Finally, we send out an END TRANSACTION step to all AMPs involved
in processing the request.
-> The contents of Spool 1 are sent back to the user as the result of
statement 1. The total estimated time is 4 minutes and 51 seconds.
Explain plan for QA_US_MASTER.ITEM:
1) First, we lock QA_US_MASTER.ITEM in view qa4_US_MASTER_VIEWS.item
for access.
2) Next, we do an all-AMPs RETRIEVE step from QA_US_MASTER.ITEM in
view qa4_US_MASTER_VIEWS.item by way of an all-rows scan with no
residual conditions into Spool 1 (group_amps), which is built
locally on the AMPs. The size of Spool 1 is estimated with high
confidence to be 1,413,284 rows (357,560,852 bytes). The
estimated time for this step is 0.40 seconds.
3) Finally, we send out an END TRANSACTION step to all AMPs involved
in processing the request.
-> The contents of Spool 1 are sent back to the user as the result of
statement 1. The total estimated time is 0.40 seconds.
Explain plan for QA_US_MASTER.MVNDR_ITEM_STR:
1) First, we lock QA_US_MASTER.MVNDR_ITEM_STR in view
qa4_US_MASTER_VIEWS.mvndr_item_str for access.
2) Next, we do an all-AMPs RETRIEVE step from
QA_US_MASTER.MVNDR_ITEM_STR in view
qa4_US_MASTER_VIEWS.mvndr_item_str by way of an all-rows scan with
no residual conditions into Spool 1 (group_amps), which is built
locally on the AMPs. The input table will not be cached in memory,
but it is eligible for synchronized scanning. The result spool
file will not be cached in memory. The size of Spool 1 is
estimated with high confidence to be 1,316,279,746 rows (
327,753,656,754 bytes). The estimated time for this step is 6
minutes and 4 seconds.
3) Finally, we send out an END TRANSACTION step to all AMPs involved
in processing the request.
-> The contents of Spool 1 are sent back to the user as the result of
statement 1. The total estimated time is 6 minutes and 4 seconds.
Explain plan for Whole query:
1) First, we lock QA_US_MASTER.ITEM in view QA_US_MASTER_VIEWS.item
for access, we lock QA_US_MASTER.LOCATION in view
qa4_US_MASTER_VIEWS.location for access, we lock
QA_US_MASTER.MVNDR_ITEM_STR in view
qa4_US_MASTER_VIEWS.mvndr_item_str for access, and we lock
QA_US_MASTER.item_str in view qa4_US_MASTER_VIEWS.item_str for
access.
2) Next, we execute the following steps in parallel.
1) We do an all-AMPs RETRIEVE step from QA_US_MASTER.LOCATION in
view qa4_US_MASTER_VIEWS.location by way of an all-rows scan
with no residual conditions into Spool 3 (all_amps)
(compressed columns allowed), which is duplicated on all AMPs.
The size of Spool 3 is estimated with high confidence to be
1,013,979 rows (20,279,580 bytes). The estimated time for
this step is 0.03 seconds.
2) We do an all-AMPs RETRIEVE step from QA_US_MASTER.ITEM in
view QA_US_MASTER_VIEWS.item by way of an all-rows scan with
a condition of ("(QA_US_MASTER.ITEM in view
QA_US_MASTER_VIEWS.item.ITEM_STAT_CD = 100) AND
(QA_US_MASTER.ITEM in view QA_US_MASTER_VIEWS.item.ACTV_FLG =
'Y')") into Spool 4 (all_amps) (compressed columns allowed)
fanned out into 14 hash join partitions, which is duplicated
on all AMPs. The size of Spool 4 is estimated with low
confidence to be 30,819,363 rows (678,025,986 bytes). The
estimated time for this step is 0.81 seconds.
3) We do an all-AMPs JOIN step from Spool 3 (Last Use) by way of an
all-rows scan, which is joined to QA_US_MASTER.item_str in view
qa4_US_MASTER_VIEWS.item_str by way of an all-rows scan with a
condition of
("(QA_US_MASTER.item_str in view
qa4_US_MASTER_VIEWS.item_str.CURR_RMETH_CD = 2) AND
((QA_US_MASTER.item_str in view
qa4_US_MASTER_VIEWS.item_str.EFF_END_DT = DATE '9999-12-31') AND
(QA_US_MASTER.item_str in view
qa4_US_MASTER_VIEWS.item_str.ACTV_FLG = 'Y'))"). Spool 3 and
QA_US_MASTER.item_str are joined using a dynamic hash join, with a
join condition of ("QA_US_MASTER.item_str.STR_LOC_ID = LOC_ID").
The input table QA_US_MASTER.item_str will not be cached in memory.
The result goes into Spool 5 (all_amps) (compressed columns
allowed), which is built locally on the AMPs into 14 hash join
partitions. The size of Spool 5 is estimated with no confidence
to be 69,133,946 rows (2,419,688,110 bytes). The estimated time
for this step is 1 minute and 8 seconds.
4) We do an all-AMPs JOIN step from Spool 4 (Last Use) by way of an
all-rows scan, which is joined to Spool 5 (Last Use) by way of an
all-rows scan. Spool 4 and Spool 5 are joined using a hash join
of 14 partitions, with a join condition of ("(ITEM_ID = ITEM_ID)
AND (ACTV_FLG = ACTV_FLG)"). The result goes into Spool 6
(all_amps) (compressed columns allowed), which is redistributed by
the hash code of (QA_US_MASTER.item_str.STR_LOC_ID,
QA_US_MASTER.item_str.ITEM_STAT_CD, QA_US_MASTER.item_str.ITEM_ID,
QA_US_MASTER.ITEM.ITEM_ID, QA_US_MASTER.LOCATION.LOC_ID) to all
AMPs into 33 hash join partitions. The size of Spool 6 is
estimated with no confidence to be 36,434,893 rows (1,603,135,292
bytes). The estimated time for this step is 9.11 seconds.
5) We do an all-AMPs RETRIEVE step from QA_US_MASTER.MVNDR_ITEM_STR
in view qa4_US_MASTER_VIEWS.mvndr_item_str by way of an all-rows
scan with a condition of ("(QA_US_MASTER.MVNDR_ITEM_STR in view
qa4_US_MASTER_VIEWS.mvndr_item_str.CURR_DSVC_TYP_CD = 3) AND
((QA_US_MASTER.MVNDR_ITEM_STR in view
qa4_US_MASTER_VIEWS.mvndr_item_str.EFF_END_DT = DATE '9999-12-31')
AND ((QA_US_MASTER.MVNDR_ITEM_STR in view
qa4_US_MASTER_VIEWS.mvndr_item_str.ACTV_FLG = 'Y') AND
(QA_US_MASTER.MVNDR_ITEM_STR in view
qa4_US_MASTER_VIEWS.mvndr_item_str.OK_TO_ORD_FLG = 'Y')))") into
Spool 7 (all_amps) (compressed columns allowed) fanned out into 33
hash join partitions, which is redistributed by the hash code of (
QA_US_MASTER.MVNDR_ITEM_STR.ITEM_ID,
QA_US_MASTER.MVNDR_ITEM_STR.STR_LOC_ID,
QA_US_MASTER.MVNDR_ITEM_STR.ITEM_STAT_CD,
QA_US_MASTER.MVNDR_ITEM_STR.ITEM_ID,
QA_US_MASTER.MVNDR_ITEM_STR.STR_LOC_ID) to all AMPs. The input
table will not be cached in memory, but it is eligible for
synchronized scanning. The size of Spool 7 is estimated with no
confidence to be 173,967,551 rows (5,914,896,734 bytes). The
estimated time for this step is 2 minutes and 23 seconds.
6) We do an all-AMPs JOIN step from Spool 6 (Last Use) by way of an
all-rows scan, which is joined to Spool 7 (Last Use) by way of an
all-rows scan. Spool 6 and Spool 7 are joined using a hash join
of 33 partitions, with a join condition of ("(STR_LOC_ID =
STR_LOC_ID) AND ((ITEM_STAT_CD = ITEM_STAT_CD) AND ((ITEM_ID =
ITEM_ID) AND ((ACTV_FLG = OK_TO_ORD_FLG) AND ((ACTV_FLG = ACTV_FLG)
AND ((EFF_END_DT = EFF_END_DT) AND ((ACTV_FLG = ACTV_FLG) AND
((OK_TO_ORD_FLG = ACTV_FLG) AND ((ITEM_ID = ITEM_ID) AND
(STR_LOC_ID = LOC_ID )))))))))"). The result goes into Spool 2
(all_amps) (compressed columns allowed), which is built locally on
the AMPs. The size of Spool 2 is estimated with no confidence to
be 12,939,628 rows (336,430,328 bytes). The estimated time for
this step is 4.00 seconds.
7) We do an all-AMPs STAT FUNCTION step from Spool 2 by way of an
all-rows scan into Spool 10, which is redistributed by hash code
to all AMPs. The result rows are put into Spool 1 (group_amps),
which is built locally on the AMPs. This step is used to retrieve
the TOP 100 rows. Load distribution optimization is used.
If this step retrieves less than 100 rows, then execute step 8.
The size is estimated with no confidence to be 100 rows (3,200
bytes).
8) We do an all-AMPs STAT FUNCTION step from Spool 2 (Last Use) by
way of an all-rows scan into Spool 10 (Last Use), which is
redistributed by hash code to all AMPs. The result rows are put
into Spool 1 (group_amps), which is built locally on the AMPs.
This step is used to retrieve the TOP 100 rows. The size is
estimated with no confidence to be 100 rows (3,200 bytes).
9) Finally, we send out an END TRANSACTION step to all AMPs involved
in processing the request.
-> The contents of Spool 1 are sent back to the user as the result of
statement 1.

Answer 1

There's no ORDER BY in your query, so you just want 100 random rows?
In Teradata the TOP is done after the full result set has been created. You should move the TOP into a Derived Table like:
select I.item_sku_nbr,L.loc_nbr,MIS.MVNDR_PRTY_ID from
QA_US_MASTER_VIEWS.item I,
qa4_US_MASTER_VIEWS.location L,
(SELECT TOP 100 * FROM qa4_US_MASTER_VIEWS.item_str) IST,
qa4_US_MASTER_VIEWS.mvndr_item_str MIS
where MIS.str_LOC_ID = L.loc_id and
mis.str_loc_id = IST.str_loc_id and
IST.str_loc_id = L.loc_id and
MIS.ITEM_STAT_CD = IST.ITEM_STAT_CD and
IST.ITEM_ID = I.ITEM_ID and
MIS.ITEM_ID = IST.ITEM_ID and
I.ITEM_STAT_CD = 100 and
IST.curr_rmeth_cd = 2 and
MIS.curr_dsvc_typ_cd = 3 and
MIS.OK_TO_ORD_FLG = 'Y' and
MIS.EFF_END_DT = DATE '9999-12-31' and
IST.EFF_END_DT = DATE '9999-12-31' and
MIS.ACTV_FLG ='Y' and
IST.ACTV_FLG ='Y' and I.ACTV_FLG='Y'