Taking forever to update a table from another

Question

I have temp table with 14k records and main table with 5 million records, I am updating main table from temp table using below SQL

UPDATE customPricing t1 
INNER JOIN customPricingIncremental t2 ON (t1.customerClass=t2.customerClass and t1.customerName=t2.customerName and t1.svcType=t2.svcType and t1.svcDuration=t2.svcDuration and t1.durationPeriod=t2.durationPeriod and t1.partNumberSKU=t2.partNumberSKU)
SET t1.customerId= t2.customerId, t1.customerNumber= t2.customerNumber, t1.custPartNumber=t2.custPartNumber, t1.sppl= t2.sppl ,t1.priceMSRP= t2.priceMSRP, t1.partnerPriceDistiDvarOEM= t2.partnerPriceDistiDvarOEM, t1.msrpSvcPrice=t2.msrpSvcPrice, t1.partnerSvcPrice=t2.partnerSvcPrice, t1.msrpBundlePrice=t2.msrpBundlePrice, t1.partnerBundlePrice=t2.partnerBundlePrice, t1.startDate=t2.startDate, t1.endDate=t2.endDate, t1.currency=t2.currency, t1.countryCode=t2.countryCode, t1.inventoryItemId=t2.inventoryItemId, t1.flexField1=t2.flexField1, t1.flexField2=t2.flexField2, t1.flexField3=t2.flexField3, t1.flexField4=t2.flexField4, t1.flexField5=t2.flexField5

CustomerClass, customerName, durationPeriod, svcDuration & partNumberSKU all are indexes on both tables with length of 10 only, there is no primary key/unique indexes for both.

It takes forever to update the table, and I get timedout in the end.

What I am doing wrong ?

Nitesh

Answer 1

Try to disable nonunique keys temporarily: ALTER TABLE customPricing DISABLE KEYS

Now run your query, and then enable them again:

ALTER TABLE customPricing ENABLE KEYS

Do this from the mysql client or a script instead of phpmyadmin as the queries might only apply to the current session.

Also, watch out for any triggers in the target table.

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