explain file structure

First-level file index (direct index) structure: There is a set of table entries in the File catalog table entry for indexing, and each table entry is registered with the disk block number where the logical record resides. The logical record is

EXPLAIN is used to return a row of information for each table in the SELECT statement. Tables are listed in the order they will be read by MySQL during query processing. EXPLAIN is used to return a row of information for each table in the SELECT

The explanation of mysql explain is clear.Of With the help of explain, you will know when to add an index to the table to use the index to search for records so that select can run faster.If the index is not properly used, you can run analyze table

The explanation of mysql explain is clear.Of With the help of explain, you will know when to add an index to the table to use the index to search for records so that select can run faster.If the index is not properly used, you can run analyze table

MySQL execution Plan explain detailed 2015-08-10 13:56:27Category: MySQLThe explain command is the primary way to see how the query optimizer decides to execute a query.This feature has limitations and does not always tell the truth, but its output

Explain shows how MySQL uses indexes to process SELECT statements and join tables. Can help select better indexes and write more optimized query statements.Parse an SQL statement first to see what

Explanation of the usage of explain in mysql MySQLexplain BitsCN.com The explanation of mysql explain is clear.Of With the help of explain, you will know when to add an index to the table to use the index to search for records so that select can run

The EXPLAINtbl_name or: EXPLAINSELECTselect_optionsEXPLAIN statement can be used as a synonym for DESCRIBE. It can also be used to obtain information about the SELECT statement to be executed by MySQL. The syntax of EXPLAINtbl_name is the same as

Learning Java friends should all know that Java from the beginning of the platform on the banner of independence, said "write, run Everywhere", in fact, to the irrelevant, the Java platform there is another independent of that is language

The instance analyzes the file structure of Java Class, And the instance analyzes java Friends who are studying Java should know that Java started from the very beginning with a platform-independent flag, saying "one write, run everywhere". In fact,