In that case, check if the query can omit the references to those columns. If not, run benchmarks to confirm if such queries are faster with parallel query turned on or turned off. In Aurora MySQL version 2, parallel query has these limitations for large object types: TEXT, BLOB, ...
Database: The default database in use at the time of the query. The database name might be blank, or might not match the database used within the query, if you used a qualified table name (for example,select ... from db_name.table_name) or if you issued aUSEstatement to switch d...
It also describes the how to manage and use the query cache, a feature that enables the Oracle BI Server to save the results of a query in cache files and then reuse those results later when a similar query is requested. Using cache, the cost of database processing must be paid only ...
MySqlConnection cannot be cast to [B]MySQL.Data.MySqlClient.MySqlConnection. [C#] How to make the Console Process delay [C#] Oracle.DataAccess issue - Unhandled exception of type System.TypeInitializationException occured in mscorlib.dll [C#] Regex - Best Validation of Domain? [C#] Upload ...
上面,我们使用-B test表明是对test这个database操作,然后用-T t1,t2表明只导出t1,t2两张表。-t 16表明使用16个线程去导出数据。-F 128是将实际的table切分成多大的chunk,这里就是128MB一个chunk。 注意:在阿里云一些需要super privilege的云上面,mydumper需要加上--no-locks参数,否则会提示没有权限操作。
Database : Users : Query sample: SET timestamp=1356056205; SELECT logo FROM storeInfo WHERE userId ='10010011010'; My question is WHY so much lock and some of them is 1+ second? Why the query spend so much time to get a read-lock? How to reduce these locks? Thanks Al...
"Simple" SQL to check for alpha or numeric charcters isn't working right "String or binary data would be truncated.\r\nThe statement has been terminated." "String or binary data would be truncated" and field specifications “Unable to enlist in the transaction” with Oracle linked server fro...
Query Profiler functionality helps trace, recreate, and troubleshoot problems in PostgreSQL Server. With the PostgreSQL Profiler tool, you can quickly and easily identify productivity bottlenecks and thus boost the overall performance and efficiency of your database system. In order to tune Postgres ...
This means that when you unpickle a QuerySet, it contains the results at the moment it was pickled, rather than the results that are currently in the database. If you only want to pickle the necessary information to recreate the QuerySet from the database at a later time, pickle the ...
Understand and analyze locks to resolve contention and increase throughputWho This Book Is ForDatabase administrators and SQL developers who are familiar with MySQL and need to participate in query tuning. While some experience with MySQL is required, no prior knowledge of query performance tuning is...