通过禁用explain,我们可以避免查询计划信息的泄露,提高查询的安全性。具体的禁用方法取决于使用的数据库适配器,我们可以根据不同的适配器来设置相应的配置项来实现目标。希望本文对您理解和使用SQL在Rails 3.2中禁用explain功能有所帮助。
|LogicalView(tables="[0000-0031].sbtest1_[000-127]",shardCount=128,sql="SELECT * FROM `sbtest1` WHERE (`id` > ?) ORDER BY `k`")| |UnionAll(concurrent=true)| |LogicalView(tables="[0000-0031].sbtest1_[000-127]",shardCount=128,sql="SELECT * FROM `sbtest1` WHERE ((`k` > ?
下面的示例输出包括创建一个名为 View1 的推荐具体化视图。XML 复制 <?xml version="1.0" encoding="utf-8"?> <dsql_query number_nodes="1" number_distributions="8" number_distributions_per_node="8"> <sql>select count(*) from ((select distinct c_last_name, c_first_name, d_date from ...
I’ve changed my query to get a more complicated plan. This is just a data dictionary view (DBA_DATA_FILES.) Plans get complicated, QUICKLY. Where to start? If you’re somewhat new to SQL tuning, you might not know where to start. We tried to give you some pointers via the ‘CPU ...
该语句用于解释SQL语句的执行计划,包括SELECT、DELETE、INSERT、REPLACE或UPDATE语句。 语法 获取SQL计划信息: EXPLAIN {LOGICALVIEW |LOGIC|SIMPLE|DETAIL|EXECUTE|PHYSICAL|OPTIMIZER|SHARDING|COST|ANALYZE|BASELINE|JSON_PLAN|ADVISOR} {SELECT statement |DELETEstatement |INSERTstatement |REPLACEstatement|UPDATEstatement}...
4.partition view --分区视图 Partition views are a legacy technology that were superceded by the partitioning option. This section of the article is provided as reference for such legacy systems. 附:oracle优化器(Optimizer) Oracle 数据库中优化器(Optimizer)是SQL分析和执行的优化工具,它负责指定SQL的执...
1 row in set, 1 warning (0.00 sec) 各列的含义如下: id: SELECT 查询的标识符. 每个 SELECT 都会自动分配一个唯一的标识符. select_type: SELECT 查询的类型. table: 查询的是哪个表 partitions: 匹配的分区 type: join 类型 possible_keys: 此次查询中可能选用的索引 ...
SQL Explain Plans in SAP HANA - Learn how to effectively use SQL Explain Plans in SAP HANA to optimize your queries and improve performance.
This tool automatically explains in plain english what your SQL query does, free of charge: Submit the query you'd like to get an automatic explenation of: Explain my query Frequently Asked Questions Need a free optimized PostgreSQL or MySQL instance?Start an Aiven database instance for free....
[sql]view plain copy print? *** 1. row *** id: 1 select_type: SIMPLE table: inventory type: ref possible_keys: item_id key: item_id key_len: 4 ref: const rows: 1 Extra: ...