SQL Server Stream Aggregate vs Hash match Aggregate
Hello, I am a new SQL Server engineer. While looking at the execution plan of a query that SUM() values of int type based on the range of a date column of datetime type, I discovered that SUM() processing is handled by Stream Aggregate and Hash match aggregate in each case. The table is composed of a Clustered Index with Date as the key. I think it changes to Hash match processing as the index search range increases, but I don't know the difference between the two processing methods and what criteria determine the processing method. Can you give me a good answer?
ghost index
Hi, I'm trying to optimize a query. Looking at the execution plan, I find that it suggests creating an index using 3 columns. Once the index was created, I rechecked the execution plan and again found the indication to create the same index even though I had already created it. it's as if he doesn't see it How is it possible? Thanks Andrea
View is taking more time and consuming 100% cpu utilization
We are using views on tables having huge records to display some information in our application but it is consuming 100% CPU utilization and taking more time to process the records. SELECT COUNT(*) FROM FRA_ITEM_FIELD_DEF--44 SELECT COUNT(*) FROM FRA_STAT_ITEM--59635520(59M) SELECT COUNT(*) FROM FRA_STAT_FIELD--536719680(536M) Available Indexes: FRA_STAT_ITEM: CREATE UNIQUE INDEX FRA_STITM_U1 ON FRA_STAT_ITEM (ID_ORIGINAL,ITEM_TYPE,SEQUENCE_NO) GO CREATE INDEX FRA_STITM_U2 ON FRA_STAT_ITEM (REFERENCE) GO FRA_STAT_FIELD: CREATE INDEX FRA_STFLD_OPT1 ON FRA_STAT_FIELD (ID_STAT_ITEM,ID_FIELD_DEF,TEXT_VALUE,DATETIME_VALUE,NUMBER_VALUE,DECIMAL_VALUE) GO FRA_STAT_FIELD: CREATE INDEX FRA_STFLD_OPT2 ON FRA_STAT_FIELD (ID_FIELD_DEF) INCLUDE (ID_STAT_ITEM,DATETIME_VALUE) GO CREATE INDEX FRA_STFLD_OPT3 ON FRA_STAT_FIELD (ID_FIELD_DEF) INCLUDE (ID_STAT_ITEM,TEXT_VALUE) GO Reported View: CREATE OR ALTER VIEW FRAUD_ALERT_STAT_HIT_VIEW AS SELECT DISTINCT STAT.ID AS ID, STAT.COMPANY AS COMPANY, STAT.TEXT_VALUE AS ACCOUNT, STAT.ITEM_TYPE AS FRAUD_ITEM_TYPE, STAT.DATETIME_VALUE AS VALUE_DATE, STAT.CREATION_TIME AS CREATION_TIME, STAT.PAYLOAD AS PAYLOAD, STAT.REFERENCE AS REFERENCE, STAT.SEQUENCE_NO AS SEQUENCE_NO, STAT.ID_MANDATOR AS ID_MANDATOR, STAT.ALERTED AS ALERTED, STAT.STATUS AS STATUS FROM ( SELECT DISTINCT FSI.ID, FSI.ITEM_TYPE, FSI1.DATETIME_VALUE, FSI2.TEXT_VALUE, FSI.COMPANY, FSI.CREATION_TIME, FSI.PAYLOAD, FSI.REFERENCE, FSI.SEQUENCE_NO, FSI.ID_MANDATOR, FSI.ALERTED, FSI.STATUS FROM FRA_STAT_ITEM FSI CROSS JOIN FRA_STAT_FIELD FSI1 CROSS JOIN FRA_STAT_FIELD FSI2 WHERE FSI1.ID_STAT_ITEM=FSI.ID AND FSI1.ID_FIELD_DEF IN (SELECT ID FROM FRA_ITEM_FIELD_DEF WHERE MAPPING='executionDate') AND FSI2.ID_STAT_ITEM=FSI.ID AND FSI2.ID_FIELD_DEF IN (SELECT ID FROM FRA_ITEM_FIELD_DEF WHERE MAPPING='debitAccount') UNION SELECT DISTINCT FSI.ID, FSI.ITEM_TYPE, FSI1.DATETIME_VALUE, FSI3.TEXT_VALUE, FSI.COMPANY, FSI.CREATION_TIME, FSI.PAYLOAD, FSI.REFERENCE, FSI.SEQUENCE_NO, FSI.ID_MANDATOR, FSI.ALERTED, FSI.STATUS FROM FRA_STAT_ITEM FSI CROSS JOIN FRA_STAT_FIELD FSI1 CROSS JOIN FRA_STAT_FIELD FSI3 WHERE FSI1.ID_STAT_ITEM=FSI.ID AND FSI1.ID_FIELD_DEF IN (SELECT ID FROM FRA_ITEM_FIELD_DEF WHERE MAPPING='executionDate') AND FSI3.ID_STAT_ITEM=FSI.ID AND FSI3.ID_FIELD_DEF IN (SELECT ID FROM FRA_ITEM_FIELD_DEF WHERE MAPPING='creditAccount') ) STAT GO Query to fetch and display record in GUI: WITH query AS (select ROW_NUMBER() OVER (order by fraudstats0_.id desc) as __hibernate_row_nr__, fraudstats0_.id as id64_, fraudstats0_.version as version64_, fraudstats0_.alert_type as alert3_64_, fraudstats0_.benef_cust_id as benef4_64_, fraudstats0_.blocked as blocked64_, fraudstats0_.company as company64_, fraudstats0_.creation_time as creation7_64_, fraudstats0_.id_mandator as id8_64_, fraudstats0_.ordering_cust_id as ordering9_64_, fraudstats0_.id_original as id10_64_, fraudstats0_.reference as reference64_, fraudstats0_.sequence_no as sequence12_64_, fraudstats0_.item_type as item13_64_, fraudstats0_.alerted as alerted64_, fraudstats0_.last_evaluation as last15_64_, fraudstats0_.last_eval_time as last16_64_, fraudstats0_.last_eval_user as last17_64_, fraudstats0_.id_live_item as id18_64_, fraudstats0_.payload as payload64_, fraudstats0_.status as status64_ from fra_stat_item fraudstats0_ where fraudstats0_.id in (select fraudstats1_.id from fraud_alert_stat_hit_view fraudstats1_ where fraudstats1_.fraud_item_type='profile.batch.trn.alert' and fraudstats1_.value_date>=@P0 and (fraudstats1_.account in (@P1 , @P2 , @P3) or fraudstats1_.account in (@P4 , @P5 , @P6))) ) SELECT * FROM query WHERE __hibernate_row_nr__ BETWEEN @P7 AND @P8 At present, Archiving/Purging the table is not possible by structure. Could anyone share some suggestion on fine tuning the view?