文章目录

通过subquery_planner查看rtable是些什么东西
- select * from test1 , test2 where test1.id2=test2.id2 ;
- select * from test1 left join test2 on test1.id2=test2.id2 ,test3,test4 where test3.id2=test4.id2 ;
- 结构体
select pg_backend_pid();
select * from pg_backend_pid();查看rtable
select * from power(1.1,1.2);
select * from generate_series(1,20000) as g,floor(random()*100) as gg,floor(random()*100),floor(random()*100) as hh;
postgres=# select * from test1,test2 where test1.id1- test1.id3>2*test2.id4;时候的TargetEntry的expr字段是啥？

通过subquery_planner查看rtable是些什么东西

select * from test1 , test2 where test1.id2=test2.id2 ;

就两个范围表

(gdb) print length(parse->rtable)
$26 = 2

(gdb) print *rte
$1 = {type = T_RangeTblEntry, rtekind = RTE_RELATION, relid = 16384, relkind = 114 'r', tablesample = 0x0, subquery = 0x0, security_barrier = false, jointype = JOIN_INNER, joinaliasvars = 0x0, functions = 0x0, funcordinality = false, tablefunc = 0x0, values_lists = 0x0, ctename = 0x0, ctelevelsup = 0, self_reference = false, coltypes = 0x0, coltypmods = 0x0, colcollations = 0x0, enrname = 0x0, enrtuples = 0, alias = 0x0, eref = 0x292f050, lateral = false, inh = true, inFromCl = true, requiredPerms = 2, checkAsUser = 0, selectedCols = 0x29530a8, insertedCols = 0x0, updatedCols = 0x0, securityQuals = 0x0}

(gdb) print *rte
$2 = {type = T_RangeTblEntry, rtekind = RTE_RELATION, relid = 16387, relkind = 114 'r', tablesample = 0x0, subquery = 0x0, security_barrier = false, jointype = JOIN_INNER, joinaliasvars = 0x0, functions = 0x0, funcordinality = false, tablefunc = 0x0, values_lists = 0x0, ctename = 0x0, ctelevelsup = 0, self_reference = false, coltypes = 0x0, coltypmods = 0x0, colcollations = 0x0, enrname = 0x0, enrtuples = 0, alias = 0x0, eref = 0x292f4d0, lateral = false, inh = true, inFromCl = true, requiredPerms = 2, checkAsUser = 0, selectedCols = 0x29533c0, insertedCols = 0x0, updatedCols = 0x0, securityQuals = 0x0}

我顺便要看一下(OpExpr) *(parse->jointree->quals)

(gdb) print (OpExpr) *(parse->jointree->quals)
$18 = {xpr = {type = T_OpExpr}, opno = 96, opfuncid = 65, opresulttype = 16, opretset = false, opcollid = 0, inputcollid = 0, args = 0x2953588, location = 43}
(gdb)

opno=96表示这是个是=

{ oid => '96', oid_symbol => 'Int4EqualOperator', descr => 'equal',oprname => '=', oprcanmerge => 't', oprcanhash => 't', oprleft => 'int4',oprright => 'int4', oprresult => 'bool', oprcom => '=(int4,int4)',oprnegate => '<>(int4,int4)', oprcode => 'int4eq', oprrest => 'eqsel',oprjoin => 'eqjoinsel' },

65表示啥啊不知道呢

{ oid => '65',proname => 'int4eq', proleakproof => 't', prorettype => 'bool',proargtypes => 'int4 int4', prosrc => 'int4eq' },

{ oid => '16', descr => 'boolean, \'true\'/\'false\'',typname => 'bool', typlen => '1', typbyval => 't', typcategory => 'B',typispreferred => 't', typarray => '_bool', typinput => 'boolin',typoutput => 'boolout', typreceive => 'boolrecv', typsend => 'boolsend',typalign => 'c' },

args里面是两个东西哦
- 那么这个args里面是啥类型的list呢？

$35 = {xpr = {type = T_Var}, varno = 1, varattno = 2, vartype = 23, vartypmod = -1, varcollid = 0, varlevelsup = 0, varnoold = 1, varoattno = 2, location = 34}

哈哈，原来是Var累心的

typedef struct Var
{Expr       xpr;Index       varno;          /* index of this var's relation in the range* table, or INNER_VAR/OUTER_VAR/INDEX_VAR */AttrNumber varattno;       /* attribute number of this var, or zero for* all attrs ("whole-row Var") */Oid           vartype;        /* pg_type OID for the type of this var */int32     vartypmod;      /* pg_attribute typmod value */Oid          varcollid;      /* OID of collation, or InvalidOid if none */Index      varlevelsup;    /* for subquery variables referencing outer* relations; 0 in a normal var, >0 means N* levels up */Index     varnoold;       /* original value of varno, for debugging */AttrNumber  varoattno;      /* original value of varattno */int         location;       /* token location, or -1 if unknown */
} Var;

/** OpExpr - expression node for an operator invocation** Semantically, this is essentially the same as a function call.** Note that opfuncid is not necessarily filled in immediately on creation* of the node.  The planner makes sure it is valid before passing the node* tree to the executor, but during parsing/planning opfuncid can be 0.*/
typedef struct OpExpr
{Expr       xpr;Oid         opno;           /* PG_OPERATOR OID of the operator */Oid            opfuncid;       /* PG_PROC OID of underlying function */Oid         opresulttype;   /* PG_TYPE OID of result value */bool       opretset;       /* true if operator returns set */Oid           opcollid;       /* OID of collation of result */Oid         inputcollid;    /* OID of collation that operator should use */List    *args;           /* arguments to the operator (1 or 2) */int         location;       /* token location, or -1 if unknown */
} OpExpr;

select * from test1 left join test2 on test1.id2=test2.id2 ,test3,test4 where test3.id2=test4.id2 ;

他一共有五个RangeTblEntry
为什么RTE_RELATION是JOIN_INNER
- 因为他默认是零，而0就是JOIN_INNER


(gdb) print *rte
$4 = {type = T_RangeTblEntry, rtekind = RTE_RELATION, relid = 16384, relkind = 114 'r', tablesample = 0x0, subquery = 0x0, security_barrier = false, jointype = JOIN_INNER, joinaliasvars = 0x0, functions = 0x0, funcordinality = false, tablefunc = 0x0, values_lists = 0x0, ctename = 0x0, ctelevelsup = 0, self_reference = false, coltypes = 0x0, coltypmods = 0x0, colcollations = 0x0, enrname = 0x0, enrtuples = 0, alias = 0x0, eref = 0x29e2468, lateral = false, inh = true, inFromCl = true, requiredPerms = 2, checkAsUser = 0, selectedCols = 0x29e2590, insertedCols = 0x0, updatedCols = 0x0, securityQuals = 0x0}

(gdb) print *rte
$6 = {type = T_RangeTblEntry, rtekind = RTE_RELATION, relid = 16387, relkind = 114 'r', tablesample = 0x0, subquery = 0x0, security_barrier = false, jointype = JOIN_INNER, joinaliasvars = 0x0, functions = 0x0, funcordinality = false, tablefunc = 0x0, values_lists = 0x0, ctename = 0x0, ctelevelsup = 0, self_reference = false, coltypes = 0x0, coltypmods = 0x0, colcollations = 0x0, enrname = 0x0, enrtuples = 0, alias = 0x0, eref = 0x29e2728, lateral = false, inh = true, inFromCl = true, requiredPerms = 2, checkAsUser = 0, selectedCols = 0x29e2838, insertedCols = 0x0, updatedCols = 0x0, securityQuals = 0x0}
(gdb)


$7 = {type = T_RangeTblEntry, rtekind = RTE_JOIN, relid = 0, relkind = 0 '\000', tablesample = 0x0, subquery = 0x0, security_barrier = false, jointype = JOIN_LEFT, joinaliasvars = 0x29e2980, functions = 0x0, funcordinality = false, tablefunc = 0x0, values_lists = 0x0, ctename = 0x0, ctelevelsup = 0, self_reference = false, coltypes = 0x0, coltypmods = 0x0, colcollations = 0x0, enrname = 0x0, enrtuples = 0, alias = 0x0, eref = 0x29e2ad0, lateral = false, inh = false, inFromCl = true, requiredPerms = 2, checkAsUser = 0, selectedCols = 0x0, insertedCols = 0x0, updatedCols = 0x0, securityQuals = 0x0}
(gdb)


$8 = {type = T_RangeTblEntry, rtekind = RTE_RELATION, relid = 24576, relkind = 114 'r', tablesample = 0x0, subquery = 0x0, security_barrier = false, jointype = JOIN_INNER, joinaliasvars = 0x0, functions = 0x0, funcordinality = false, tablefunc = 0x0, values_lists = 0x0, ctename = 0x0, ctelevelsup = 0, self_reference = false, coltypes = 0x0, coltypmods = 0x0, colcollations = 0x0, enrname = 0x0, enrtuples = 0, alias = 0x0, eref = 0x29e2de0, lateral = false, inh = true, inFromCl = true, requiredPerms = 2, checkAsUser = 0, selectedCols = 0x29e2f08, insertedCols = 0x0, updatedCols = 0x0, securityQuals = 0x0}

$9 = {type = T_RangeTblEntry, rtekind = RTE_RELATION, relid = 24579, relkind = 114 'r', tablesample = 0x0, subquery = 0x0, security_barrier = false, jointype = JOIN_INNER, joinaliasvars = 0x0, functions = 0x0, funcordinality = false, tablefunc = 0x0, values_lists = 0x0, ctename = 0x0, ctelevelsup = 0, self_reference = false, coltypes = 0x0, coltypmods = 0x0, colcollations = 0x0, enrname = 0x0, enrtuples = 0, alias = 0x0, eref = 0x29e3050, lateral = false, inh = true, inFromCl = true, requiredPerms = 2, checkAsUser = 0, selectedCols = 0x29e3178, insertedCols = 0x0, updatedCols = 0x0, securityQuals = 0x0}

结构体


typedef struct RangeTblEntry
{NodeTag        type;RTEKind        rtekind;        /* see above *//** XXX the fields applicable to only some rte kinds should be merged into* a union.  I didn't do this yet because the diffs would impact a lot of* code that is being actively worked on.  FIXME someday.*//** Fields valid for a plain relation RTE (else zero):** As a special case, RTE_NAMEDTUPLESTORE can also set relid to indicate* that the tuple format of the tuplestore is the same as the referenced* relation.  This allows plans referencing AFTER trigger transition* tables to be invalidated if the underlying table is altered.*/Oid         relid;          /* OID of the relation */char       relkind;        /* relation kind (see pg_class.relkind) */struct TableSampleClause *tablesample;    /* sampling info, or NULL *//** Fields valid for a subquery RTE (else NULL):*/Query    *subquery;       /* the sub-query */bool     security_barrier;   /* is from security_barrier view? *//** Fields valid for a join RTE (else NULL/zero):** joinaliasvars is a list of (usually) Vars corresponding to the columns* of the join result.  An alias Var referencing column K of the join* result can be replaced by the K'th element of joinaliasvars --- but to* simplify the task of reverse-listing aliases correctly, we do not do* that until planning time.  In detail: an element of joinaliasvars can* be a Var of one of the join's input relations, or such a Var with an* implicit coercion to the join's output column type, or a COALESCE* expression containing the two input column Vars (possibly coerced).* Within a Query loaded from a stored rule, it is also possible for* joinaliasvars items to be null pointers, which are placeholders for* (necessarily unreferenced) columns dropped since the rule was made.* Also, once planning begins, joinaliasvars items can be almost anything,* as a result of subquery-flattening substitutions.*/JoinType jointype;       /* type of join */List     *joinaliasvars;  /* list of alias-var expansions *//** Fields valid for a function RTE (else NIL/zero):** When funcordinality is true, the eref->colnames list includes an alias* for the ordinality column.  The ordinality column is otherwise* implicit, and must be accounted for "by hand" in places such as* expandRTE().*/List      *functions;      /* list of RangeTblFunction nodes */bool        funcordinality; /* is this called WITH ORDINALITY? *//** Fields valid for a TableFunc RTE (else NULL):*/TableFunc  *tablefunc;/** Fields valid for a values RTE (else NIL):*/List      *values_lists;   /* list of expression lists *//** Fields valid for a CTE RTE (else NULL/zero):*/char       *ctename;        /* name of the WITH list item */Index       ctelevelsup;    /* number of query levels up */bool     self_reference; /* is this a recursive self-reference? *//** Fields valid for CTE, VALUES, ENR, and TableFunc RTEs (else NIL):** We need these for CTE RTEs so that the types of self-referential* columns are well-defined.  For VALUES RTEs, storing these explicitly* saves having to re-determine the info by scanning the values_lists. For* ENRs, we store the types explicitly here (we could get the information* from the catalogs if 'relid' was supplied, but we'd still need these* for TupleDesc-based ENRs, so we might as well always store the type* info here).  For TableFuncs, these fields are redundant with data in* the TableFunc node, but keeping them here allows some code sharing with* the other cases.** For ENRs only, we have to consider the possibility of dropped columns.* A dropped column is included in these lists, but it will have zeroes in* all three lists (as well as an empty-string entry in eref).  Testing* for zero coltype is the standard way to detect a dropped column.*/List    *coltypes;       /* OID list of column type OIDs */List     *coltypmods;     /* integer list of column typmods */List       *colcollations;  /* OID list of column collation OIDs *//** Fields valid for ENR RTEs (else NULL/zero):*/char       *enrname;        /* name of ephemeral named relation */double        enrtuples;      /* estimated or actual from caller *//** Fields valid in all RTEs:*/Alias      *alias;          /* user-written alias clause, if any */Alias       *eref;           /* expanded reference names */bool      lateral;        /* subquery, function, or values is LATERAL? */bool     inh;            /* inheritance requested? */bool        inFromCl;       /* present in FROM clause? */AclMode        requiredPerms;  /* bitmask of required access permissions */Oid         checkAsUser;    /* if valid, check access as this role */Bitmapset  *selectedCols;  /* columns needing SELECT permission */Bitmapset  *insertedCols;    /* columns needing INSERT permission */Bitmapset  *updatedCols; /* columns needing UPDATE permission */List    *securityQuals;  /* security barrier quals to apply, if any */
} RangeTblEntry;

select pg_backend_pid();

rtable是个空的啊！！
下面这个也是空的！

select generate_series(1,20000) as g,floor(random()*100) as gg,
floor(random()*100),floor(random()*100);

select * from pg_backend_pid();查看rtable

select * from pg_backend_pid();

果然是RTE_FUNCTION啊！

687          if (rte->rtekind == RTE_JOIN)
(gdb) p *rte
$11 = {type = T_RangeTblEntry, rtekind = RTE_FUNCTION, relid = 0, relkind = 0 '\000', tablesample = 0x0, subquery = 0x0, security_barrier = false, jointype = JOIN_INNER, joinaliasvars = 0x0, functions = 0x2712ee8, funcordinality = false, tablefunc = 0x0, values_lists = 0x0, ctename = 0x0, ctelevelsup = 0, self_reference = false, coltypes = 0x0, coltypmods = 0x0, colcollations = 0x0, enrname = 0x0, enrtuples = 0, alias = 0x0, eref = 0x2712d00, lateral = false, inh = false, inFromCl = true, requiredPerms = 2, checkAsUser = 0, selectedCols = 0x0, insertedCols = 0x0, updatedCols = 0x0, securityQuals = 0x0}
(gdb)

select * from power(1.1,1.2);

这也是RTE_FUNCTION了！

select * from generate_series(1,20000) as g,floor(random()100) as gg,floor(random()100),floor(random()*100) as hh;

上面的rtable是4个RTE_FUNCTION啊！

postgres=#  select * from generate_series(1,20000) as g,floor(random()*100) as gg,floor(random()*100),floor(random()*100) as hh;g   | gg | floor | hh
-------+----+-------+----1 | 30 |    96 | 962 | 30 |    96 | 963 | 30 |    96 | 964 | 30 |    96 | 965 | 30 |    96 | 966 | 30 |    96 | 967 | 30 |    96 | 968 | 30 |    96 | 969 | 30 |    96 | 9610 | 30 |    96 | 9611 | 30 |    96 | 9612 | 30 |    96 | 96

postgres=# select * from test1,test2 where test1.id1- test1.id3>2*test2.id4;时候的TargetEntry的expr字段是啥？


(gdb) p length(parse->targetList)
$3 = 6
(gdb) print ((Node *)(list_head(parse->targetList)->data.ptr_value))->type
$4 = T_TargetEntry
(gdb) print ((TargetEntry *)(list_head(parse->targetList)->data.ptr_value))
$5 = (TargetEntry *) 0x1a474d0
(gdb) p ($5->expr)
$6 = (Expr *) 0x1a24ff0
(gdb) p ($5->expr)->type
$7 = T_Var
(gdb) p (Var)($5->expr)->type
$8 = {xpr = {type = T_Var}, varno = 1, varattno = 1, vartype = 23, vartypmod = -1, varcollid = 0, varlevelsup = 0, varnoold = 1, varoattno = 1, location = 7}
(gdb)

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通过subquery_planner查看rtable是些什么东西

文章目录

通过subquery_planner查看rtable是些什么东西

select * from test1 , test2 where test1.id2=test2.id2 ;

select * from test1 left join test2 on test1.id2=test2.id2 ,test3,test4 where test3.id2=test4.id2 ;

结构体

select pg_backend_pid();

select * from pg_backend_pid();查看rtable

select * from power(1.1,1.2);

select * from generate_series(1,20000) as g,floor(random()100) as gg,floor(random()100),floor(random()*100) as hh;

postgres=# select * from test1,test2 where test1.id1- test1.id3>2*test2.id4;时候的TargetEntry的expr字段是啥？

通过subquery_planner查看rtable是些什么东西相关推荐

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