[TOC] # FLASHBACK DATABASE ## 描述 用于從回收站中恢復被刪除的DATABASE。 ## 前置條件 回收站需要處于開啟狀態，可以通過 `show variables like 'recyclebin';` 來查看回收站是否開啟。 ~~~ OceanBase(admin@test)> show variables like 'recyclebin'; +---------------+-------+ | Variable_name | Value | +---------------+-------+ | recyclebin | ON | +---------------+-------+ 1 row in set (0.00 sec) ~~~ 果回收站處于關閉狀態，可以通過 `set recyclebin = on;` 來開啟。回收站中的表沒有被實際刪除，仍然會占用資源，如果需要徹底刪除，可以執行 `purge recyclebin;` ## 格式 ~~~ FLASHBACK DATABASE object_name TO BEFORE DROP [RENAME TO db_name]; ~~~ ## 參數解釋 <table data-tag="table" id="table-i89-kmq-68n" class="table"><colgroup width="360" span="1" data-tag="col" id="col-3fj-lv1-43d" colwidth="1*" colnum="1" colname="col1" style="width:50%" class="col"></colgroup><colgroup width="360" span="1" data-tag="col" id="col-tg9-xxx-ams" colwidth="1*" colnum="2" colname="col2" style="width:50%" class="col"></colgroup><thead id="thead-hxb-xv1-7t4" class="thead"><tr id="tr-ofl-a5h-wx1"><th id="td-8gp-y5m-n5p"><p id="p-ezd-ar1-xg1"><b>參數</b></p></th><th id="td-8f6-smx-heh"><p id="p-47l-fyz-zud"><b>解釋</b></p></th></tr></thead><tbody data-tag="tbody" id="tbody-aqy-50o-4t0" class="tbody"><tr data-tag="tr" id="tr-ing-q93-07z" class="tr"><td data-tag="td" id="td-0yg-46y-iaj" class="td"><p id="p-f2c-jy2-4pz">object_name</p></td><td data-tag="td" id="td-wup-efx-s3p" class="td"><p data-tag="p" id="p-p72-jys-3yl" class="p">指定要恢復的object名稱，不支持指定DATABASE名稱。恢復DATABASE時，也會將DATABASE下面的表、索引等都恢復出來。</p></td></tr><tr data-tag="tr" id="tr-1lv-4ki-nft" class="tr"><td data-tag="td" id="td-a9k-d2s-03c" class="td"><p id="p-p0m-0iu-u8i">RENAME to</p></td><td data-tag="td" id="td-icj-q6i-lks" class="td"><p data-tag="p" id="p-5ya-frg-cah" class="p">恢復時將DATABASE重命名。</p></td></tr></tbody></table> ## 示例 * 從回收站中恢復刪除的DATABASE。 ~~~ OceanBase(admin@test)> create database da; Query OK, 1 row affected (0.03 sec) OceanBase(admin@test)> drop database da; Query OK, 0 rows affected (0.04 sec) OceanBase(admin@test)> show recyclebin; +--------------------------------------------------+---------------+----------+----------------------------+ | OBJECT_NAME | ORIGINAL_NAME | TYPE | CREATETIME | +--------------------------------------------------+---------------+----------+----------------------------+ | __recycle_$_1_1099511628829_18446744073709551615 | da | DATABASE | 2017-10-20 17:36:15.838771 | +--------------------------------------------------+---------------+----------+----------------------------+ 1 row in set (0.02 sec) OceanBase(admin@test)> flashback database __recycle_$_1_1099511628829_18446744073709551615 to before drop; Query OK, 0 rows affected (0.03 sec) ~~~