在视图中使用hstore比较转储和还原PostgreSQL数据库失败

我有一个比较两个

hstore

列的视图

当我转储并还原此数据库时，还原失败，并显示以下错误消息：

Importing /tmp/hstore_test_2014-05-12.backup...
pg_restore: [archiver (db)] Error while PROCESSING TOC:
pg_restore: [archiver (db)] Error from TOC entry 172; 1259 1358132 VIEW hstore_test_view xxxx
pg_restore: [archiver (db)] could not execute query: ERROR:  operator does not exist: public.hstore = public.hstore
LINE 2:  SELECT NULLIF(hstore_test_table.column1, hstore_test_table....
                ^
HINT:  No operator matches the given name and argument type(s). You might need to add explicit type casts.
    Command was: CREATE VIEW hstore_test_view AS
 SELECT NULLIF(hstore_test_table.column1, hstore_test_table.column2) AS "nullif"
   FROM hst...
pg_restore: [archiver (db)] could not execute query: ERROR:  relation "hstore_test_schema.hstore_test_view" does not exist
    Command was: ALTER TABLE hstore_test_schema.hstore_test_view OWNER TO xxxx;

我可以通过以下步骤在PostgreSQL 9.3.0中创建此错误：

CREATE DATABASE hstore_test;

\c hstore_test

CREATE EXTENSION hstore WITH SCHEMA public;

CREATE SCHEMA hstore_test_schema;

CREATE TABLE hstore_test_schema.hstore_test_table(
   id int,
   column1 hstore,
   column2 hstore,
   PRIMARY KEY( id )
);

CREATE VIEW hstore_test_schema.hstore_test_view AS
SELECT NULLIF(column1, column2) AS comparison FROM hstore_test_schema.hstore_test_table;

为完整起见，转储和恢复过程如下所示：

pg_dump -U xxxx -h localhost -f /tmp/hstore_test_2014-05-12.backup -Fc hstore_test
psql -U xxxx -h localhost -d postgres -c "DROP DATABASE hstore_test"
psql -U xxxx -h localhost -d postgres -c "CREATE DATABASE hstore_test"
pg_restore -U xxxx -h localhost -d hstore_test /tmp/hstore_test_2014-05-12.backup

pg_restore-l/tmp/hstore_test_2014-05-12。备份

建议在创建视图之前启用

hstore

扩展：

;
; Archive created at Mon May 12 11:18:32 2014
;     dbname: hstore_test
;     TOC Entries: 15
;     Compression: -1
;     Dump Version: 1.12-0
;     Format: CUSTOM
;     Integer: 4 bytes
;     Offset: 8 bytes
;     Dumped from database version: 9.3.0
;     Dumped by pg_dump version: 9.3.0
;
;
; Selected TOC Entries:
;
2074; 1262 1358002 DATABASE - hstore_test xxxx
7; 2615 1358003 SCHEMA - hstore_test_schema xxxx
5; 2615 2200 SCHEMA - public postgres
2075; 0 0 COMMENT - SCHEMA public postgres
2076; 0 0 ACL - public postgres
173; 3079 11787 EXTENSION - plpgsql 
2077; 0 0 COMMENT - EXTENSION plpgsql 
174; 3079 1358004 EXTENSION - hstore 
2078; 0 0 COMMENT - EXTENSION hstore 
171; 1259 1358124 TABLE hstore_test_schema hstore_test_table xxxx
172; 1259 1358132 VIEW hstore_test_schema hstore_test_view xxxx
2069; 0 1358124 TABLE DATA hstore_test_schema hstore_test_table xxxx
1960; 2606 1358131 CONSTRAINT hstore_test_schema hstore_test_table_pkey xxxx

顺便说一句，将

NULLIF（col1，col2）

替换为

col1=col2

似乎会使错误消失，尽管它是对

pg\u restore

所抱怨类型的显式比较。

这是一个PostgreSQL错误

在模式中创建表时，

pg_dump

正在将

search_路径

设置为排除

public

。这是正常的。当它转储引用不在

搜索路径上的对象时，它会显式地对它们进行模式限定，以便它们工作

它适用于
=
情况，因为
pg_dump
看到
=
在这种情况下实际上是
操作符（public.=）
，并以这种形式转储它：

CREATE VIEW hstore_test_view AS
 SELECT (hstore_test_table.column1 OPERATOR(public.=) hstore_test_table.column2) AS comparison
   FROM hstore_test_table;

但是，
pg_dump
无法对通过
nullif
伪函数隐式使用的运算符执行此操作。这将导致以下伪命令序列：

CREATE EXTENSION IF NOT EXISTS hstore WITH SCHEMA public;
...
SET search_path = hstore_test_schema, pg_catalog;
...
CREATE VIEW hstore_test_view AS
 SELECT NULLIF(hstore_test_table.column1, hstore_test_table.column2) AS comparison
   FROM hstore_test_table;

pg_dump
仅使用
pg_catalog.pg_get_viewdef
函数转储视图，因此这可能需要服务器后端修复程序

最简单的解决方法是不使用
nullif
，而是用更详细但等效的
大小写替换它：

CASE WHEN column1 = column2 THEN NULL ELSE column1 END;

语法没有像我们使用显式
运算符（public.=）
那样提供模式限定
nullif
伪函数运算符的方法，因此修复看起来并不简单

我预计同样的问题会影响到
最大的
和
最小的
，可能也会影响到
不同的
，但事实并非如此。即使在运行时它们不在
search\u路径
上，它们似乎也能找到所需的运算符，但如果在视图定义时运算符不在search\u路径上，则不会失败。这表明他们可能正在使用类型的b-tree操作符类，通过目录中的类型条目（通过表的属性找到）来查找操作符。（更新：检查来源，是的，他们就是这么做的）。大概
nullif
也应该这样做，但事实并非如此

相反，它死于：

hstore_test=# \set VERBOSITY verbose
hstore_test=# CREATE VIEW hstore_test_schema.hstore_test_view AS
SELECT NULLIF(column1, column2) AS comparison FROM hstore_test_schema.hstore_test_table;
ERROR:  42883: operator does not exist: public.hstore = public.hstore
LINE 2: SELECT NULLIF(column1, column2) AS comparison FROM hstore_te...
               ^
HINT:  No operator matches the given name and argument type(s). You might need to add explicit type casts.
LOCATION:  op_error, parse_oper.c:722

当我在那里设置断点时，陷阱位于：

Breakpoint 1, op_error (pstate=pstate@entry=0x1189f38, op=op@entry=0x1189c10, oprkind=oprkind@entry=98 'b', arg1=arg1@entry=97207, arg2=arg2@entry=97207, 
    fdresult=FUNCDETAIL_NOTFOUND, location=location@entry=58) at parse_oper.c:706
706     {
(gdb) bt
#0  op_error (pstate=pstate@entry=0x1189f38, op=op@entry=0x1189c10, oprkind=oprkind@entry=98 'b', arg1=arg1@entry=97207, arg2=arg2@entry=97207, fdresult=FUNCDETAIL_NOTFOUND, 
    location=location@entry=58) at parse_oper.c:706
#1  0x000000000051a81b in oper (pstate=pstate@entry=0x1189f38, opname=opname@entry=0x1189c10, ltypeId=ltypeId@entry=97207, rtypeId=rtypeId@entry=97207, 
    noError=noError@entry=0 '\000', location=location@entry=58) at parse_oper.c:440
#2  0x000000000051ad34 in make_op (pstate=pstate@entry=0x1189f38, opname=0x1189c10, ltree=ltree@entry=0x118a528, rtree=0x118a590, location=58) at parse_oper.c:770
#3  0x00000000005155e1 in transformAExprNullIf (a=0x1189bc0, pstate=0x1189f38) at parse_expr.c:1021
#4  transformExprRecurse (pstate=pstate@entry=0x1189f38, expr=0x1189bc0) at parse_expr.c:244
#5  0x0000000000517484 in transformExpr (pstate=0x1189f38, expr=<optimized out>, exprKind=exprKind@entry=EXPR_KIND_SELECT_TARGET) at parse_expr.c:116
#6  0x000000000051ff30 in transformTargetEntry (pstate=pstate@entry=0x1189f38, node=0x1189bc0, expr=expr@entry=0x0, exprKind=exprKind@entry=EXPR_KIND_SELECT_TARGET, 
    colname=0x1189ba0 "comparison", resjunk=resjunk@entry=0 '\000') at parse_target.c:94
#7  0x00000000005212df in transformTargetList (pstate=pstate@entry=0x1189f38, targetlist=<optimized out>, exprKind=exprKind@entry=EXPR_KIND_SELECT_TARGET)
    at parse_target.c:167
#8  0x00000000004ef594 in transformSelectStmt (stmt=0x11899f0, pstate=0x1189f38) at analyze.c:942
#9  transformStmt (pstate=0x1189f38, parseTree=0x11899f0) at analyze.c:243
#10 0x00000000004f0a2d in parse_analyze (parseTree=0x11899f0, 
    sourceText=sourceText@entry=0x114e6b0 "CREATE VIEW hstore_test_schema.hstore_test_view AS\nSELECT NULLIF(column1, column2) AS comparison FROM hstore_test_schema.hstore_test_table;", paramTypes=paramTypes@entry=0x0, numParams=numParams@entry=0) at analyze.c:100
#11 0x000000000057cc4e in DefineView (stmt=stmt@entry=0x114f7e8, 
    queryString=queryString@entry=0x114e6b0 "CREATE VIEW hstore_test_schema.hstore_test_view AS\nSELECT NULLIF(column1, column2) AS comparison FROM hstore_test_schema.hstore_test_table;") at view.c:385
#12 0x000000000065b1cf in ProcessUtilitySlow (parsetree=parsetree@entry=0x114f7e8, 
    queryString=0x114e6b0 "CREATE VIEW hstore_test_schema.hstore_test_view AS\nSELECT NULLIF(column1, column2) AS comparison FROM hstore_test_schema.hstore_test_table;", 
    context=<optimized out>, params=params@entry=0x0, completionTag=completionTag@entry=0x7fffc98c9990 "", dest=<optimized out>) at utility.c:1207
#13 0x000000000065a54e in standard_ProcessUtility (parsetree=0x114f7e8, queryString=<optimized out>, context=<optimized out>, params=0x0, dest=<optimized out>, 
    completionTag=0x7fffc98c9990 "") at utility.c:829

断点1，操作错误（pstate=pstate@entry=0x1189f38，op=op@entry=0x1189c10，oprkind=oprkind@entry=98'b'，arg1=arg1@entry=97207，arg2=arg2@entry=97207, 
fdresult=FUNCDETAIL\u未找到，位置=location@entry=58）在解析运算c:706
706     {
（gdb）英国电信
#0操作错误（pstate=pstate@entry=0x1189f38，op=op@entry=0x1189c10，oprkind=oprkind@entry=98'b'，arg1=arg1@entry=97207，arg2=arg2@entry=97207，fdresult=FUNCDETAIL\u未找到，
位置=location@entry=58）在解析运算c:706
#1 0x000000000051a81b正在运行（pstate=pstate@entry=0x1189f38，opname=opname@entry=0x1189c10，ltypeId=ltypeId@entry=97207，rtypeId=rtypeId@entry=97207, 
无误=noError@entry=0'\000'，位置=location@entry=58）在解析运算时c:440
#2 0x000000000051ad34在make_op（pstate）中=pstate@entry=0x1189f38，opname=0x1189c10，ltree=ltree@entry=0x118a528，rtree=0x118a590，位置=58）在解析操作c:770
#3解析表达式c:1021处的transformAExprNullIf（a=0x1189bc0，pstate=0x1189f38）中的0x000000000005155E1
#4转换表达式（pstate）=pstate@entry=0x1189f38，expr=0x1189bc0）在解析表达式c:244处
#transformExpr中的5 0x0000000000517484（pstate=0x1189f38，expr=，exprKind=exprKind@entry=EXPR\u KIND\u SELECT\u TARGET）在parse\u EXPR.c:116处
#transformTargetEntry（pstate）中的6 0x000000000051ff30=pstate@entry=0x1189f38，节点=0x1189bc0，expr=expr@entry=0x0，exprKind=exprKind@entry=EXPR\u KIND\u SELECT\u TARGET，
colname=0x1189ba0“比较”，resjunk=resjunk@entry=0'\000'），位于解析_目标。c:94
#transformTargetList（pstate）中的7 0x0000000000521DF=pstate@entry=0x1189f38，targetlist=，exprKind=exprKind@entry=EXPR\u种类\u选择\u目标）
在parse_target.c:167
#在analyze.c:942处的transformSelectStmt（stmt=0x11899f0，pstate=0x1189f38）中的8 0x00000000004ef594
#位于analyze.c:243的9 transformStmt（pstate=0x1189f38，parseTree=0x11899f0）
#解析分析中的10 0x00000000004f0a2d（解析树=0x11899f0，
源文本=sourceText@entry=0x114e6b0“创建视图hstore_test_schema.hstore_test_VIEW AS\n从hstore_test_schema.hstore_test_table；中选择NULLIF（第1列，第2列）作为比较”，参数类型=paramTypes@entry=0x0，numParams=numParams@entry=0）在分析时。c:100
#定义视图中的11 0x000000000057cc4e（stmt=stmt@entry=0x114f7e8，
质询=queryString@entry=0x114e6b0“创建视图hstore_test_schema.hstore_test_VIEW AS\n选择NULLIF（第1列、第2列）作为与视图中hstore_test_schema.hstore_test_table；的比较”）。c:385
#ProcessUtilitySlow（parsetree）中的12 0x000000000065b1cf=parsetree@entry=0x114f7e8，
queryString=0x114e6b0“创建视图hstore_测试_架构。hstore_测试_视图作为\n从hstore_测试_架构。hstore_测试_表格中选择NULLIF（第1列，第2列）作为比较；”，
上下文=，参数=params@entry=0x0，completionTag=completionTag@entry=0x7fffc98c9990“”，目标=）位于实用程序c:1207
#13标准_ProcessUtility中的0x000000000065a54e（语法树=0x114f7e8，查询字符串=，上下文=，参数=0x0，目的地=，
completionTag=0x7fffc98c9990“”），位于utility.c:829

因此，眼前的问题看起来像是
transformAExprNullIf
无法通过b-树opclass和typecache使用操作数类型查找运算符。
我现在提出的是pgsql错误。非常有趣，您的解决方法非常有效，谢谢。2019，导出时错误仍然存在