CODEWITHSUNDEEP
mysqlsqldatabasesql-update
user3489398
user3489398

Reputation: 9

Database challenge: How to Update 1 million records efficiently?

I am struggling to update my massive database but my wamp/Heidisql keeps crashing due to this large update/comparisons.

I have two database tables: main table "member_all" (contains 3 million records) and child table:"mobile_results" (contains 9,000 records). The database structure of tables look like this:

Main Table ("member_all")

id int(11),
name varchar(255),
phoneWork varchar(255),
phoneMobile  varchar(255),
phoneMobileNetwork varchar(255)

Data in table looks like this:

id name      phoneWork      phoneMobile   phoneMobileNetwork 
1  bill      061090999990   0789867676    Null
3  billsaasa 06109094399990 076689867676  Null

Child Table : ("mobile_results")

id int(11) autoincrement,
phoneMobile varchar(255),
phoneMobileNetwork  varchar(255)

Data in mobile_results looks like this:

id     phoneMobile  phoneMobileNetwork
8789   0789867676   Orange     
238789 076689867676 O2

All my mobile network data for 9,000 mobile number is stored in "mobile_results" but when i try to compare both these table ,i get stuck and my wamp/Heidi sql crashes?

My question is :

How can i populate "member_all" with "phoneMobileNetwork" values from "mobile_results" efficiently?

Here are the queries i have tried:

Query 1

i divided my query using limit .This is slow and would also take 1 week to compare 9,000 records from mobile_results.

update  member_all,mobile_results 
set member_all.phoneMobileNetwork=mobile_results.phoneMobileNetwork  
where member_all.phoneMobile in  
(SELECT phoneMobile FROM mobile_results limit 1,10);

Query 2

update  member_all,mobile_results 
set member_all.phoneMobileNetwork=mobile_results.phoneMobileNetwork  
where member_all.phoneMobile in  
(SELECT phoneMobile FROM mobile_results where id <10);

Same not good for large number of records.

PLEASE help me how can i update records my "member_all" table efficiently in one go.

I would appreciate you help in this regard.

Upvotes: 0

Views: 714

Answers (2)

Arion
Arion

Reputation: 31239

You could try joing the tables on the update. No EXISTS, no IN. Like this:

update member_all AS ma
  JOIN mobile_results ms on ma.phoneMobile=ms.phoneMobile
  SET member_all.phoneMobileNetwork=mobile_results.phoneMobileNetwork

Reference:

Upvotes: 0

VJ Hil
VJ Hil

Reputation: 904

Can you just try this.I think using Exist will be faster

update  member_all
set phoneMobileNetwork=
(select phoneMobileNetwork  from mobile_results where 
member_all.phoneMobile=mobile_results.phoneMobile)
WHERE EXISTS
(
select 1 from mobile_results where 
member_all.phoneMobile=mobile_results.phoneMobile);

Upvotes: 1

Related Questions