COUNT(*) AS num FROM student_info GROUP BY student_id ORDER BY create_time DESC LIMIT 100; # 5.265 s # 如果出现 this is incompatible with sql_mode=only_full_group_by 等错误信息,可执行下面的语句 SELECT @@sql_mode;
从MySQL 5.7.5开始,默认SQL mode模式包括 ONLY_FULL_GROUP_BY。(在5.7.5之前,MySQL不检测功能依赖性,ONLY_FULL_GROUP_BY默认情况下不启用。 6、HAVING :对VT5应用HAVING筛选器,只有为true的组插入到VT6。 HAVING同GROUP BY一样,MySQL拓展SQL标准以允许HAVING可以使用别名和非列表表达式。 7、SELECT:将VT6每一...
2(1.5)). If a gene was upregulated in multiple clusters, it is only shown once in the cluster block where it has the biggest fold change. (b) Gene set enrichment analysis of selected Gene Ontology (GO) terms and KEGG and Reactome pathways (top) and published CD8+...
The “What add-ons do I have?” item is now available only in the Help menu. The same item in the Options menu has been removed due to redundancy. The custom setting of drums now overrides Multi-Drums. The Chord Builder (Progression Builder/Chord Picker) now always opens in the MultiPi...
LC_CTYPEshould be correct. Mainly when you use unicode borders. ncurses doesn't display unicode borders (produced bypsql) without correct setting of this variable. Is possible to check a value 'C.UTF8'. When you use a option--only-for-tables, then ...
It is enable by default and concern on TABLE export type. COMPILE_SCHEMA By default Ora2Pg will only export valid PL/SQL code. You can force Oracle to compile again the invalidated code to get a chance to have it obtain the valid status and then be able to export it. Enable this ...
PG_THREAD_WAIT_STATUS allows you to test the block waiting status about the backend thread and auxiliary thread of the current instance.The waiting statuses in the wait_s
Run the undo l2-multicast static-group group-address x.x.x.x command to delete unnecessary multicast entries and check whether the alarm hwMCastTableLoadAbnormalResume is generated. If so, go to step 4. If not, go to step 3. Collect trap, log, and configuration information, and contact ...
-- WARNING: executed with a non-superuser role, the query inspect only index on tables you are granted to read.-- WARNING: rows with is_na = 't' are known to have bad statistics ("name" type is not supported).-- This query is compatible with PostgreSQL 8.2 and afterSELECT current_...
评估index-only扫描代价的时候会用到这个值。 我们保留老的统计信息,插入1倍元组,看下规划器得到的基数是多少: 代码语言:javascript 复制 INSERT INTO flights_copy SELECT * FROM flights; SELECT count(*) FROM flights_copy; count −−−−−−−− 429734 (1 row) EXPLAIN SELECT * FROM flig...