//Description:
//Create Date: 2020-01-18 23:20:08
//Author: channy
//create
PortalRun (pquery.c)
PortalRunMulti
PortalRunUtility (utility.c)
ProcessUtility
standard_ProcessUtility
ProcessUtilitySlow
transformCreateStmt (parse_utilcmd.c)
transformColumnDefinition (在ColumnDef中记录generated，值为default)
DefineRelation
transformRelOptions
NewRelationCreateToastTable
//create table testtable (height integer, width integer, area integer generated always as (height * width) stored);
DefineRelation (tablecmds.c)
//数据准备
(权限检査oid valid? tablespaceid valid? heaptuple valid?)
transformRelOptions (把options list改写成pg_class中reloptions字段的格式)
heap_reloptions (校验)
MergeAttributes (对继承表合并属性，该语句中没有继承表)
BuildDescForRelation (创建tupleDesc结构用于pg_attribute系统表)
(对属性定义链表中的每一个属性进行处理，査看是否有默认值、表达式或约束检査)
//写数据
heap_create_with_catalog (heap.c, 创建表的物理文件并修改相应的系统表)
//初始化表数据
heap_create (创建文件到relcache中)
heapam_relation_set_new_filenode (在base/对应数据库oid/目录下创建新文件)
//写系统表数据
AddNewRelationType (写pg_type)
TypeCreate (pg_type.c)
CatalogTupleInsert (indexing.c)
simple_heap_insert (heapam.c)
heap_insert
GenerateTypeDependencies (写pg_depend)
AddNewRelationTuple (写pg_class)
AddNewAttributeTuples (写pg_attribute)
StoreConstraints (pg_constraint, 此语句中该表不改变; pg_attrdef, 增加虚拟列的默认值记录)
//处理constraints，虚拟列的计算表达式存储在这里
AddRleationNewConstraints (处理表中约束与默认值)
cookConstraint (把表达式转换成可存储的结构，同时更新系统表pg_class中constraint的数量)
//其它
(处理分区表)
StoreCataloglnheritance (对继承表存储继承关系)
PS: 系统表结构
pg_type ???
pg_class 存储表、索引、视图等的属性
pg_attribute 存储所有表每一列的属性
pg_attrdef 存储列的默认值
[pg_depend] (https://www.postgresql.org/docs/12/catalog-pg-depend.html) 存储依赖关系
Breakpoint 2, heap_create_with_catalog (
relname=0x7ffff5e655f0 "testtable", relnamespace=2200,
reltablespace=0, relid=0, reltypeid=0, reloftypeid=0, ownerid=10,
accessmtd=2, tupdesc=0x1a20660, cooked_constraints=0x0,
relkind=114 'r', relpersistence=112 'p', shared_relation=false,
mapped_relation=false, oncommit=ONCOMMIT_NOOP, reloptions=0,
use_user_acl=true, allow_system_table_mods=false, is_internal=false,
relrewrite=0, typaddress=0x0) at heap.c:1095
Breakpoint 3, cookDefault (pstate=0x1a1df88, raw_default=0x1a08980,
atttypid=1043, atttypmod=9, attname=0x7f4522c5bb54 "area",
attgenerated=115 's') at heap.c:2983
postgres=# select * from pg_type limit 5 offset 411;
oid | typname | typnamespace | typowner | typlen | typbyval | typtype | typcategory | typispreferred | typisdefined | typdelim | typrelid | typelem | typarray | t
ypinput | typoutput | typreceive | typsend | typmodin | typmodout | typanalyze | typalign | typstorage | typnotnull | typbasetype | typtypmod | typndims |
typcollation | typdefaultbin | typdefault | typacl
-------+------------+--------------+----------+--------+----------+---------+-------------+----------------+--------------+----------+----------+---------+----------+--
---------+------------+-------------+-------------+----------+-----------+------------------+----------+------------+------------+-------------+-----------+----------+-
-------------+---------------+------------+--------
16461 | testtable | 2200 | 10 | -1 | f | c | C | f | t | , | 16459 | 0 | 16460 | r
ecord_in | record_out | record_recv | record_send | - | - | - | d | x | f | 0 | -1 | 0 |
0 | | |
16460 | _testtable | 2200 | 10 | -1 | f | b | A | f | t | , | 0 | 16461 | 0 | a
rray_in | array_out | array_recv | array_send | - | - | array_typanalyze | d | x | f | 0 | -1 | 0 |
0 | | |
(2 rows)
width是普通列；area是虚拟列，在atthasdef中和普通列不同，attgenerated中有标记stored
postgres=# select * from pg_attribute where attname = 'area' or attname = 'width';
attrelid | attname | atttypid | attstattarget | attlen | attnum | attndims | attcacheoff | atttypmod | attbyval | attstorage | attalign | attnotnull | atthasdef | atth
asmissing | attidentity | attgenerated | attisdropped | attislocal | attinhcount | attcollation | attacl | attoptions | attfdwoptions | attmissingval
----------+---------+----------+---------------+--------+--------+----------+-------------+-----------+----------+------------+----------+------------+-----------+-----
----------+-------------+--------------+--------------+------------+-------------+--------------+--------+------------+---------------+---------------
16459 | width | 23 | -1 | 4 | 2 | 0 | -1 | -1 | t | p | i | f | f | f
| | | f | t | 0 | 0 | | | |
16459 | area | 23 | -1 | 4 | 3 | 0 | -1 | -1 | t | p | i | f | t | f
| | s | f | t | 0 | 0 | | | |
(2 rows)
create的表中包含有虚拟列时，该表会增加
postgres=# select * from pg_attrdef;
oid | adrelid | adnum |
adbin
-------+---------+-------+----------------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------
16462 | 16459 | 3 | {OPEXPR :opno 514 :opfuncid 141 :opresulttype 23 :opretset false :opcollid 0 :inputcollid 0 :args ({VAR :varno 1 :varattno 1 :vartype 23 :var
typmod -1 :varcollid 0 :varlevelsup 0 :varnoold 1 :varoattno 1 :location 89} {VAR :varno 1 :varattno 2 :vartype 23 :vartypmod -1 :varcollid 0 :varlevelsup 0 :varnoold 1
:varoattno 2 :location 98}) :location 96}
(1 row)
记录虚拟列的依赖信息
postgres=# select * from pg_depend where objid=16479;
classid | objid | objsubid | refclassid | refobjid | refobjsubid | deptype
---------+-------+----------+------------+----------+-------------+---------
1259 | 16479 | 0 | 2615 | 2200 | 0 | n
1259 | 16479 | 3 | 1259 | 16479 | 1 | a
1259 | 16479 | 3 | 1259 | 16479 | 2 | a
(3 rows)
//update testtable set width = 8 where height = 3;
transformTopLevelStmt (analyze.c)
transformOptionalSelectInto
transformStmt
transformUpdateStmt
transformUpdateTargetList (pg12+虚拟列也放入要更新的list中)
//insert into testtable values(12,2);
ExecModifyTable (nodeModifyTable.c)
ExecInsert (pg12+ExecComputeStoredGenerated)
table_tuple_insert (tableam.h)
heapam_tuple_insert (heapam_handler.c)
heap_insert (heapam.c)
XLogInsert
//ExecUpdate (pg12+ExecComputeStoredGenerated)
pg有自己的Expr格式和处理流程
ExecComputeStoredGenerated (nodeModifyTable.c)
ExecPrepareExpr
ExecInitExpr
ExprEvalPushStep
slot_getallattrs (tuptable.h)
slot_getsomeattrs
slot_getsomeattrs_int (execTuples.c，获取值的地址到slot的tts_values中)
tts_buffer_heap_getsomeattrs
ExecEvalExpr
ExecInterpExprStillValid (execExprInterp.c)
ExecInterpExpr
//create table testtable (height integer, width integer, area integer generated always as (height * width) stored);
(gdb) set $stmt = (CreateStmt *)((RawStmt *)(parsetree_list->head.data->ptr_value))->stmt
(gdb) p *$stmt
$6 = {type = T_CreateStmt, relation = 0x11bafc8, tableElts = 0x11bb230, inhRelations = 0x0, partbound = 0x0, partspec = 0x0,
ofTypename = 0x0, constraints = 0x0, options = 0x0, oncommit = ONCOMMIT_NOOP, tablespacename = 0x0, accessMethod = 0x0,
if_not_exists = false}
(gdb) p *(RangeVar *)($stmt->relation)
$7 = {type = T_RangeVar, catalogname = 0x0, schemaname = 0x0, relname = 0x11bafa0 "testtable", inh = true, relpersistence = 112 'p',
alias = 0x0, location = 13}
(gdb) p *(Node *)($stmt->tableElts->head.data->ptr_value)
$9 = {type = T_ColumnDef}
(gdb) p *(ColumnDef *)($stmt->tableElts->head.data->ptr_value)
$10 = {type = T_ColumnDef, colname = 0x11bb020 "height", typeName = 0x11bb118, inhcount = 0, is_local = true, is_not_null = false,
is_from_type = false, storage = 0 '\000', raw_default = 0x0, cooked_default = 0x0, identity = 0 '\000', identitySequence = 0x0,
generated = 0 '\000', collClause = 0x0, collOid = 0, constraints = 0x0, fdwoptions = 0x0, location = 24}
(gdb) p *(ColumnDef *)($stmt->tableElts->head->next.data->ptr_value)
$11 = {type = T_ColumnDef, colname = 0x11bb268 "width", typeName = 0x11bb360, inhcount = 0, is_local = true, is_not_null = false,
is_from_type = false, storage = 0 '\000', raw_default = 0x0, cooked_default = 0x0, identity = 0 '\000', identitySequence = 0x0,
generated = 0 '\000', collClause = 0x0, collOid = 0, constraints = 0x0, fdwoptions = 0x0, location = 40}
(gdb) p *(ColumnDef *)($stmt->tableElts->head->next->next.data->ptr_value)
$12 = {type = T_ColumnDef, colname = 0x11bb478 "area", typeName = 0x11bb570, inhcount = 0, is_local = true, is_not_null = false,
is_from_type = false, storage = 0 '\000', raw_default = 0x0, cooked_default = 0x0, identity = 0 '\000', identitySequence = 0x0,
generated = 0 '\000', collClause = 0x0, collOid = 0, constraints = 0x11bb9a8, fdwoptions = 0x0, location = 55}
(gdb) set $colwidth = (ColumnDef *)($stmt->tableElts->head->next.data->ptr_value)
(gdb) set $colarea = (ColumnDef *)($stmt->tableElts->head->next.data->ptr_value)
(gdb) p *$colwidth->typeName
$13 = {type = T_TypeName, names = 0x11bb2d8, typeOid = 0, setof = false, pct_type = false, typmods = 0x0, typemod = -1,
arrayBounds = 0x0, location = 46}
(gdb) p *$colarea->typeName
$14 = {type = T_TypeName, names = 0x11bb2d8, typeOid = 0, setof = false, pct_type = false, typmods = 0x0, typemod = -1,
arrayBounds = 0x0, location = 46}
//insert into testtable values(6, 9);
(gdb) p *(InsertStmt *)((RawStmt *)(parsetree_list->head.data->ptr_value))->stmt
$5 = {type = T_InsertStmt, relation = 0x2c4ee78, cols = 0x0,
selectStmt = 0x2c4efc8, onConflictClause = 0x0, returningList = 0x0,
withClause = 0x0, override = OVERRIDING_NOT_SET}
(gdb) set $stmt = (InsertStmt *)((RawStmt *)(parsetree_list->head.data->ptr_value))->stmt
(gdb) p *(RangeVar *)($stmt->relation)
$7 = {type = T_RangeVar, catalogname = 0x0, schemaname = 0x0,
relname = 0x2c4ee50 "testtable", inh = true, relpersistence = 112 'p',
alias = 0x0, location = 12}
(gdb) p *(SelectStmt *)($stmt->selectStmt)
$9 = {type = T_SelectStmt, distinctClause = 0x0, intoClause = 0x0,
targetList = 0x0, fromClause = 0x0, whereClause = 0x0,
groupClause = 0x0, havingClause = 0x0, windowClause = 0x0,
valuesLists = 0x2c4f108, sortClause = 0x0, limitOffset = 0x0,
limitCount = 0x0, lockingClause = 0x0, withClause = 0x0,
op = SETOP_NONE, all = false, larg = 0x0, rarg = 0x0}
(gdb) set $sstmt = (SelectStmt *)($stmt->selectStmt)
(gdb) p *(Node *)($sstmt->valuesLists->head.data->ptr_value)
$10 = {type = T_List}
(gdb) set $vl = (List *)($sstmt->valuesLists->head.data->ptr_value)
(gdb) p *(Node *)($vl->head.data->ptr_value)
$11 = {type = T_A_Const}
(gdb) p *(A_Const *)($vl->head.data->ptr_value)
$12 = {type = T_A_Const, val = {type = T_Integer, val = {ival = 6,
str = 0x6 <error: Cannot access memory at address 0x6>}},
location = 29}
(gdb) p *(A_Const *)($vl->head->next.data->ptr_value)
$13 = {type = T_A_Const, val = {type = T_Integer, val = {ival = 9,
str = 0x9 <error: Cannot access memory at address 0x9>}},
location = 31}