SELECTt.nameAS表名,SUM(p.rows)AS记录数FROMsys.tablesAStINNERJOINsys.partitionsASpONt.object_id=p.object_idWHEREt.is_ms_shipped=0ANDp.index_idIN(0,1)GROUPBYt.name; 1. 2. 3. 4. 5. 在上面的代码中,我们使用了sys.tables和sys.part
October 13, 2007 at 6:49 pm #182826 Comments posted to this topic are about the itemCount rows in all tables over time SQL 2K only Signature is NULL Viewing 0 posts You must be logged in to reply to this topic.Login to reply
SELECT SQL_CALC_FOUND_ROWS * FROM student WHERE Gender='男' LIMIT 1;-- 查1行 SELECT FOUND_ROWS();-- 返回表中所有 Gender='男' 的总行数 8 2.不加 SQL_CALC_FOUND_ROWS 的时候,返回查询返回的总数据行数,包含LIMIT。 ROW_COUNT(): row_count()查询同一连接上一条dml语句返回的行数,中间不能...
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra +---+---+---+---+---+---+---+---+---+-+ | 1 | SIMPLE | a | ALL | idx_orderid | NULL | NULL | NULL | 1967647 | Using filesort | | 1 | SIMPLE | o | eq_ref | ...
p.rows AS rowcounts, SUM(a.total_pages) * 8 AS totalspaceKB, SUM(a.used_pages) * 8 AS usedspaceKB, (SUM(a.total_pages) - SUM(a.used_pages)) * 8 AS unusedspaceKB, getdate() as captureddatetime FROM sys.tables t INNER JOIN sys.indexes i ON t.OBJECT_ID = i.object_id ...
mysql>showglobal statuslike' created_tmp%';+---+---+|Variable_name|Value|+---+---+|Created_tmp_disk_tables|21197||Created_tmp_files|58||Created_tmp_tables|1771587|+---+---+mysql>show variables like'tmp_table_size';+---+---+|Variable_name|Value|+---+---...
FROM ALL_TABLES A,(SELECT TABLESPACE_NAME, MAX(BYTES) AS BIG_CHUNK FROM DBA_FREE_SPACE GROUP BY TABLESPACE_NAME ) F WHERE F.TABLESPACE_NAME = A.TABLESPACE_NAME AND A.NEXT_EXTENT > F.BIG_CHUNK UNION SELECT A.INDEX_NAME, A.NEXT_EXTENT, A.TABLESPACE_NAME ...
其他的Oracle Hints ALL_ROWS FIRST_ROWS RULE USE_NL USE_MERGE USE_HASH 等等。 这是一个很有技巧性的工作。建议只针对特定的,少数的SQL进行hint的优化。 33. 几种不能使用索引的WHERE子句(1)下面的例子中,‘!=’ 将不使用索引 ,索引只能告诉你什么存在于表中,而不能告诉你什么不存在于表中。
Add Time in SQL HH:MM:SS to another HH:MM:SS Adding a column to a large (100 million rows) table with default constraint adding a extra column in a pivot table created uisng T-SQL Pivot Table query Adding a partition scheme to an existing table. Adding a Value to a 'date' Colu...
Let’s count all rows in the table. Solution COUNT(*)counts the total number of rows in the table: SELECTCOUNT(*)ascount_pet FROMpet; Here’s the result: Instead of passing in the asterisk as the argument, you can use the name of a specific column: ...