Test whether to use INT or DateTime for MySQL query time period

Source: Internet
Author: User

During MySQL query time period, it will be more efficient to select INT, or will it be more efficient to select DateTime? To solve this problem, we will perform a test to see whether INT or DateTime should be used in the MySQL query period.

Environment:

Windows XP
PHP Version 5.2.9
MySQL servers 5.1

Step 1: Create a table date_test with a non-fixed length and an int time)

Create table 'test'. 'date _ test '(
'Id' int not null AUTO_INCREMENT,
'Start _ time' int not null,
'Some _ content' VARCHAR (255) not null,
Primary key ('id ')
) ENGINE = InnoDB;

Step 2: Create the second table date_test2 with a fixed length and int time)

Create table 'test'. 'date _ test2 '(
'Id' int not null AUTO_INCREMENT,
'Start _ time' int not null,
'Some _ content' CHAR (255) not null,
Primary key ('id ')
) ENGINE = InnoDB;

Step 3: Create the third table date_test3varchar and datetime time)

Create table 'test'. 'date _ test3 '(
'Id' int not null AUTO_INCREMENT,
'Start _ time' datetime not null,
'Some _ content' VARCHAR (255) not null,
Primary key ('id ')
) ENGINE = InnoDB;

Step 4: Create the fourth table date_test3char and datetime time)

Create table 'test'. 'date _ test4 '(
'Id' int not null AUTO_INCREMENT,
'Start _ time' datetime not null,
'Some _ content' CHAR (255) not null,
Primary key ('id ')
) ENGINE = InnoDB;

OK. Now let's start the test. The environment is php. insert 1 million pieces of data into each table first. The number of inserts is divided into 200 times, and 5000 entries are imported into the database each time.

Table 1 execution record: Page running time: 26.5997889042 seconds, an interesting phenomenon found during insertion: SELECT count (id) FROM 'date _ test' WHERE 1 results in 100 w, the direct select * from 'date _ test' is 1,000,374 results. Later, we can see that this is a possible close value. Please refer to MySQL FAQ 3.11 ).

Table 2 execution records: Page running time: 62.3908278942 seconds. This record is 1,000,066.

Table 3 Execution records: Page running time: 30.2576560974 seconds. This time, there are 1,000,224 records.

Table 4 Execution record: Page running time: 67.5393900871 seconds. This time, there are 1,000,073 records.

Now, the start_time fields of the four tables are indexed one by one.

Test the update of the four tables. update 100 records respectively and record the time:

Table 1: Page running time: 2.62180089951 seconds (int time)

Table 2: Page running time: 2.5475358963 seconds fixed length, int time)

Table 3: Page running time: 2.45077300072 seconds varchar, datetime time)

Table 4: Page running time: 2.82798409462 s char, datetime time)

Test the reading of the four tables, select 100 random records respectively, query with the primary key id as the condition, and record the time:

Table 1: Page running time: 0.382651090622 seconds (int time)

Table 2: Page running time: 0.542181015015 seconds fixed length, int time)

Table 3: Page running time: 0.334048032761 seconds varchar, datetime time)

Table 4: Page running time: 0.506206989288 s char, datetime time)

Test the reading of four tables, select 10 random records respectively, query with star_time as the condition, and record the time:

Table 1: Page running time: 30.1972880363 seconds (int time)

Table 2: Page running time: 65.1926910877 seconds fixed length, int time)

Table 3: Page running time: 39.7210869789 seconds varchar, datetime time)

Table 4: Page running time: 70.4632740021 s char, datetime time)

Because the amount is small, it makes sense for us to make small changes by default.

Conclusion:

If a large number of queries such as select * from table where time> XX exist in large data volumes, it is meaningful to use int for datetime in MySQL5.1.
 

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