connect username/password@database 用指定用户连接数据库 define variable 定义一个置换变量,显示所有置换变量 describe object 给指定对象一个描述 descconnect 断开连接 edit 显示一个编辑sql缓冲区的文本编辑器 execute procedure 执行指定的存储过程 exit application 退出,application将关闭pl/sql developer host command...
仍然对C语言中的声明和定义感到困惑:如果头文件类似于: #ifndef _BASIC_H_ #define _BASIC_H_ void test(); extern int i; //define or declare #endif 而两个源文件f1.c和f2.c包含这个头文件,那么一个源文件需要定义变量"i“。但是如果头文件是这样的: #ifndef _BASIC_H_ #define _BASIC_H_ void...
postgres=# \h create event Command: CREATE EVENT TRIGGER Description: define a new event trigger Syntax: CREATE EVENT TRIGGER name ON event [ WHEN filter_variable IN (filter_value [, ... ]) [ AND ... ] ] EXECUTE PROCEDURE function_name() 目前事件触发器,支持的command tag如下 首先要创...
EXECUTE IMMEDIATE SQL_string [INTO {define_variable[, define_variable]...| record}] [USING [IN | OUT | IN OUT] bind_argument 1. 2. 3. [, [IN | OUT | IN OUT] bind_argument]...]; 我们可以把这个语句用于除了多行查询以外的任何SQL语句或者PL/SQL块。如果SQL_string后面带了分号,这就会...
PostgreSQL天然集群,多个集群可以组成集簇,有点类似军队的连、团、旅这样的组织规则。对于我们日常学习使用的单节点则是单个集簇单个集群,自己就是集群。 PostgreSQL如何管理这种集群规则?答案是通过一个无符号4个字节的标识进行管理,一个对象就是集群里的一个数据库。
(ColumnDef); n->colname = $1; n->typeName = $2; n->inhcount = 0; n->is_local = true; n->is_not_null = false; n->is_from_type = false; n->is_from_parent = false; n->storage = 0; n->raw_default = NULL; n->cooked_default = NULL; n->collClause = (Collate...
/** Module Load Callback*/void_PG_init(void){/* Define custom GUC variables */DefineCustomIntVariable("auth_delay.milliseconds","Milliseconds to delay before reporting authentication failure",NULL,&auth_delay_milliseconds,0,0,INT_MAX/1000,PGC_SIGHUP,GUC_UNIT_MS|POLAR_GUC_IS_UNCHANGABLE,NULL...
1 /* parser_init() Initialize to parse one query string */ 2 void parser_init(base_yy_extra_type *yyext) { 3 yyext->parsetree = NIL; /* in case grammar forgets to set it */ 4 } 我们先通过一个标准SELECT语句分析lex和bison输出的scan.c和gram.c代码,从gram.y中给出的SSELECT语句定...
define variableforuse by custom script -f FILENAMEreadtransaction script from FILENAME -j NUM number of threads(default: 1)-l write transactiontimesto log file -M{simple|extended|prepared}protocolforsubmitting queries to server(default: simple)-ndonot run VACUUM before tests ...
* Var - expression node representing a variable (ie, a table column) * * Note: during parsing/planning, varnoold/varoattno are always just copies * of varno/varattno. At the tail end of planning, Var nodes appearing in * upper-level plan nodes are reassigned to point to the outputs ...