reindex all tables

SQLite tutorial (5): Index and data analysis/cleanup, sqlite Data Analysis I. Create an index: In SQLite, the SQL syntax for index creation is basically the same as that of most other relational databases, because here is just an example usage: Copy

First, create an index: In SQLite, the SQL syntax to create an index is essentially the same as most other relational databases, because this is simply a sample usage: Copy Code code as follows: Sqlite> CREATE TABLE testtable

View all data tables> Use ChatRoomSwitched to db ChatRoom> Show collectionsAccountChatSystem. indexesSystem. users Create a data table> Db. createCollection ("Account "){"OK": 1} > Db. createCollection ("Test", {capped: true, size: 10000}) {"OK": 1}{

In the Android development environment, ADB is our most frequently used debugging tool for Android development, and its use is of course what our Android developers have to master.ADB overviewAndroid Debug Bridge,android Debug Bridge, abbreviated as

PostgreSQL tutorial (14): database maintenance, postgresql tutorial I. Disk Space Restoration: In PostgreSQL, the data rows deleted or updated using the delete and update statements are not actually deleted, the physical address of the old data row

First, restore disk space: In PostgreSQL, data rows that are deleted or updated using the Delete and UPDATE statements are not actually deleted, but only the state of the row is deleted or expired on the physical address of the old version of the

I. Disk Space Restoration: In PostgreSQL, the data rows deleted or updated using the delete and update statements are not actually deleted, the physical address of the old data row sets the row status to deleted or expired. Therefore, when data in a

I. restore disk space In PostgreSQL, the data rows deleted or updated using the delete and update statements are not actually deleted, the physical address of the old data row sets the row status to deleted or expired. Therefore, when data in a

First of all, pandas's author is the author of this book.For NumPy, the object we are dealing with is the matrixPandas is encapsulated based on the NumPy, pandas is a two-dimensional table (tabular, spreadsheet-like), and the difference between the

SQL statement optimization principles:◆ 1. Use indexes to traverse tables fasterThe index created by default is a non-clustered index, but sometimes it is not optimal. In a non-clustered index, data is physically stored on the data page randomly.