這期內容當中小編將會給大家帶來有關怎么理解MySQL 5.7 Online DDL Overview，文章內容豐富且以專業的角度為大家分析和敘述，閱讀完這篇文章希望大家可以有所收獲。

成都創新互聯公司服務項目包括賀州網站建設、賀州網站制作、賀州網頁制作以及賀州網絡營銷策劃等。多年來，我們專注于互聯網行業，利用自身積累的技術優勢、行業經驗、深度合作伙伴關系等，向廣大中小型企業、政府機構等提供互聯網行業的解決方案，賀州網站推廣取得了明顯的社會效益與經濟效益。目前，我們服務的客戶以成都為中心已經輻射到賀州省份的部分城市，未來相信會繼續擴大服務區域并繼續獲得客戶的支持與信任！

Operation	In-Place?	Rebuilds Table?	Permits Concurrent DML?	Only Modifies Metadata?	Notes
CREATE INDEX, ADD INDEX	Yes*	No*	Yes	No	Restrictions apply for FULLTEXT indexes; see next row.
ADD FULLTEXT INDEX	Yes*	No*	No	No	Adding the first FULLTEXT index rebuilds the table if there is no user-defined FTS_DOC_ID column. Subsequent FULLTEXT indexes may be added on the same table without rebuilding the table.
ADD SPATIAL INDEX	Yes	No	No	No
RENAME INDEX	Yes	No	Yes	Yes	Only modifies table metadata.
DROP INDEX	Yes	No	Yes	Yes	Only modifies table metadata.
OPTIMIZE TABLE	Yes*	Yes	Yes	No	In-place operation is not supported for tables with FULLTEXT indexes.
Set column default value	Yes	No	Yes	Yes	Only modifies table metadata.
Change auto-incrementvalue	Yes	No	Yes	No*	Modifies a value stored in memory, not the data file.
Add foreign key constraint	Yes*	No	Yes	Yes	The INPLACE algorithm is supported when foreign_key_checks is disabled. Otherwise, only theCOPY algorithm is supported.
Drop foreign key constraint	Yes	No	Yes	Yes	foreign_key_checks can be enabled or disabled.
Rename column	Yes*	No	Yes*	Yes	To permit concurrent DML, keep the same data type and only change the column name.ALGORITHM=INPLACE is not supported for renaming a generated column.
Add column	Yes*	Yes*	Yes*	No	Concurrent DML is not permitted when adding an auto-increment column. Data is reorganized substantially, making it an expensive operation. ALGORITHM=INPLACE is supported for adding a virtual generated column but not for adding a stored generated column. Adding a virtual generated column does not require a table rebuild.
Drop column	Yes	Yes*	Yes	No	Data is reorganized substantially, making it an expensive operation. ALGORITHM=INPLACE is supported for dropping a generated column. Dropping a virtual generated column does not require a table rebuild.
Reorder columns	Yes	Yes	Yes	No	Data is reorganized substantially, making it an expensive operation.
Change ROW_FORMATproperty	Yes	Yes	Yes	No	Data is reorganized substantially, making it an expensive operation.
Change KEY_BLOCK_SIZEproperty	Yes	Yes	Yes	No	Data is reorganized substantially, making it an expensive operation.
Make column NULL	Yes	Yes*	Yes	No	Rebuilds the table in place. Data is reorganized substantially, making it an expensive operation.
Make column NOT NULL	Yes*	Yes	Yes	No	Rebuilds the table in place. STRICT_ALL_TABLES or STRICT_TRANS_TABLES SQL_MODE is required for the operation to succeed. The operation fails if the column contains NULL values. The server prohibits changes to foreign key columns that have the potential to cause loss of referential integrity. SeeSection 13.1.8, “ALTER TABLE Syntax”. Data is reorganized substantially, making it an expensive operation.
Change column data type	No*	Yes	No	No	VARCHAR size may be increased using online ALTER TABLE. See Modifying Column Properties for more information.
Add primary key	Yes*	Yes*	Yes	No	Rebuilds the table in place. Data is reorganized substantially, making it an expensive operation.ALGORITHM=INPLACE is not permitted under certain conditions if columns have to be converted toNOT NULL.
Drop primary key and add another	Yes	Yes	Yes	No	Data is reorganized substantially, making it an expensive operation.
Drop primary key	No	Yes	No	No	Only ALGORITHM=COPY supports dropping a primary key without adding a new one in the same ALTER TABLE statement.
Convert character set	No	Yes*	No	No	Rebuilds the table if the new character encoding is different.
Specify character set	No	Yes*	No	No	Rebuilds the table if the new character encoding is different.
Rebuild with FORCE option	Yes*	Yes	Yes	No	Uses ALGORITHM=INPLACE. ALGORITHM=INPLACE is not supported for tables with FULLTEXT indexes.
“null” rebuild using ALTER TABLE ... ENGINE=INNODB	Yes*	Yes	Yes	No	Uses ALGORITHM=INPLACE. ALGORITHM=INPLACE is not supported for tables with FULLTEXT indexes.
Set STATS_PERSISTENT,STATS_AUTO_RECALC,STATS_SAMPLE_PAGESpersistent statistics options	Yes	No	Yes	Yes	Only modifies table metadata.
ALTER TABLE … ENCRYPTION	No	Yes	No	Yes
Drop a STORED column	Yes	Yes*	Yes	No	Rebuilds the table in place.
Modify STORED column order	Yes	Yes*	Yes	No	Rebuilds the table in place.
Add a STORED column	Yes	Yes*	Yes	No	Rebuilds the table in place.
Drop a VIRTUAL column	Yes	No	Yes	Yes
Modify VIRTUAL column order	Yes	No	Yes	Yes
Add a VIRTUAL column	Yes	No	Yes	Yes

此列顯示哪些操作允許使用ALGORITHM=INPLACE子句。“Rebuilds Table？”列顯示哪些操作可以重建表。對于使用就地算法的操作，表將就地重建。對于不支持就地算法的操作，使用表復制方法重新生成表。

“允許并發DML？”列顯示完全在線執行的操作。您可以指定LOCK=NONE來斷言在DDL操作期間允許并發DML。MySQL在可能的情況下自動允許并發DML。

在所有聯機DDL操作期間允許并發查詢。您可以指定LOCK=SHARED來斷言在DDL操作期間允許并發查詢。MySQL在可能的情況下自動允許并發查詢。

“注釋”列提供附加信息，并解釋與其他列的“是/否”值相關的異常和依賴關系。星號表示異常或依賴項。

上述就是小編為大家分享的怎么理解MySQL 5.7 Online DDL Overview了，如果剛好有類似的疑惑，不妨參照上述分析進行理解。如果想知道更多相關知識，歡迎關注創新互聯行業資訊頻道。

網站名稱：怎么理解MySQL5.7OnlineDDLOverview
文章位置：http://www.yijiale78.com/article0/gcsioo.html

成都網站建設公司_創新互聯，為您提供做網站、服務器托管、微信小程序、ChatGPT、軟件開發、用戶體驗

廣告

聲明：本網站發布的內容（圖片、視頻和文字）以用戶投稿、用戶轉載內容為主，如果涉及侵權請盡快告知，我們將會在第一時間刪除。文章觀點不代表本網站立場，如需處理請聯系客服。電話：028-86922220；郵箱：631063699@qq.com。內容未經允許不得轉載，或轉載時需注明來源： 創新互聯