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List of Big-O for PHP functions
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isset/array_key_exists is much faster than in_array and array_search
+(union) is a bit faster than array_merge (and looks nicer). But it does work differently so keep that in mind.
shuffle is on the same Big-O tier as array_rand
array_pop/array_push is faster than array_shift/array_unshift due t...
MySQL INSERT INTO table VALUES.. vs INSERT INTO table SET
...ll, both syntaxes are equivalent. The first is SQL standard, the second is MySQL's extension.
So they should be exactly equivalent performance wise.
http://dev.mysql.com/doc/refman/5.6/en/insert.html says:
INSERT inserts new rows into an existing table. The INSERT ... VALUES and INSERT ... SET...
How can you determine how much disk space a particular MySQL table is taking up?
Is there a quick way to determine how much disk space a particular MySQL table is taking up? The table may be MyISAM or Innodb.
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Convert JS date time to MySQL datetime
Does anyone know how to convert JS dateTime to MySQL datetime? Also is there a way to add a specific number of minutes to JS datetime and then pass it to MySQL datetime?
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How to debug PDO database queries?
...ments to Rails, but that the benefit is much heavier in PostgreSQL than in MySQL. He said that this is because MySQL doesn't actually create the query plan until you execute the prepared query.
– Nathan Long
Jul 20 '11 at 13:46
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How to Get True Size of MySQL Database?
I would like to know how much space does my MySQL database use, in order to select a web host.
I found the command SHOW TABLE STATUS LIKE 'table_name' so when I do the query, I get something like this:
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Dropping Unique constraint from MySQL table
How can I drop the "Unique Key Constraint" on a column of a MySQL table using phpMyAdmin?
10 Answers
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Types in MySQL: BigInt(20) vs Int(20)
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See http://dev.mysql.com/doc/refman/8.0/en/numeric-types.html
INT is a four-byte signed integer.
BIGINT is an eight-byte signed integer.
They each accept no more and no fewer values than can be stored in their respective number of by...
What does `unsigned` in MySQL mean and when to use it?
What does "unsigned" mean in MySQL and when should I use it?
1 Answer
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【BLE技术内幕】BLE技术揭秘 - 创客硬件开发 - 清泛IT论坛，有思想、有深度
...个时间点把数据包发送出去，怎么保证数据的完整性，ACK如何接收，如何进行重传，以及如何对链路进行管理和控制等等。LL层只负责把数据发出去或者收回来，对数据进行怎样的解析则交给上面的GAP或者ATTHost Controller Interface，...