CODEWITHSUNDEEP
mysqlfull-table-scan
uldis.zarins
uldis.zarins

Reputation: 416

mysql searching in various fields with OR performing full table scan

I have 3 tables (not writing all and actual field names)

I need to search for phone numbers so i try this - if i serch for one phone number for example in container.phone_1 

SELECT *
FROM contract JOIN client
     ON contract.client_id = client.id
     JOIN container
     ON contract.contract_nr = container.contract_nr
WHERE container.phone_1 LIKE '264%' 

id  select_type table   type    possible_keys   key key_len ref rows    filtered    Extra
-------------------------------------------------------------------------------------------------------------
1   SIMPLE  container   range   contract_nr,phone_1 phone_1 63  NULL    912 100.00  Using where
1   SIMPLE  contract    ref contract_nr,client_id   contract_nr 26  container.contract_nr   1   100.00  
1   SIMPLE  client  eq_ref  PRIMARY,id  PRIMARY 3   contract.client_id  1   100.00

but when i start to add phone numbers from client using OR

SELECT * 
FROM contract JOIN client 
    ON contract.client_id = client.id 
    JOIN container ON contract.contract_nr = container.contract_nr 
WHERE (
    container.phone_1 LIKE '264%' OR 
    client.phone_2 LIKE '264%' OR 
    client_phone_3 LIKE '264%'
)

EXPLAIN EXTENDED:

id  select_type table   type    possible_keys   key key_len ref rows     filtered   Extra
-------------------------------------------------------------------------------------------------------------
1   SIMPLE  container   ALL k_ligums,k_telef    NULL    NULL    NULL    32113   100.00  
1   SIMPLE  contract    ref contract_nr,client_id   contract_nr 26  za.zaao_konteineri.k_ligums 1   100.00  
1   SIMPLE  client  eq_ref  PRIMARY,id  PRIMARY 3   contract.client_id  1   100.00  Using where

I have indexed all the fields that are used to join tables and that are used to search for. I also tried to create multiple-column index for client and container tables having all the search rows included - no difference.

How can i avoid scanning of 32113 rows for container table?

Upvotes: 0

Views: 90

Answers (1)

Sunil Harak
Sunil Harak

Reputation: 249

use and instead of where.

SELECT * FROM contract JOIN client ON contract.client_id = client.id JOIN container ON contract.contract_nr = container.contract_nr AND (container.phone_1 LIKE '264%' client.phone_2 LIKE '264%' OR client_phone_3 LIKE '264%')

Upvotes: -1

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