How to construct expression parsing by PostgreSQL 01/18 Update SLTechnology News&Howtos

How to construct expression parsing by PostgreSQL

2025-01-18 Update From: SLTechnology News&Howtos shulou NAV: SLTechnology News&Howtos > Database >

Shulou(Shulou.com)05/31 Report--

< 3; 调用栈 (gdb) bt #0 ExecBuildProjectionInfo (targetList=0x1cc7550, econtext=0x1c8f408, slot=0x1c8f710, parent=0x1c8f1f0, inputDesc=0x7f8386bb6ab8) at execExpr.c:355 #1 0x00000000006e60d5 in ExecAssignProjectionInfo (planstate=0x1c8f1f0, inputDesc=0x7f8386bb6ab8) at execUtils.c:468 #2 0x00000000006e613c in ExecConditionalAssignProjectionInfo (planstate=0x1c8f1f0, inputDesc=0x7f8386bb6ab8, varno=1) at execUtils.c:493 #3 0x00000000006e23f5 in ExecAssignScanProjectionInfo (node=0x1c8f1f0) at execScan.c:240 #4 0x0000000000700afc in ExecInitIndexScan (node=0x1ba8a18, estate=0x1c8efd8, eflags=16) at nodeIndexscan.c:962 #5 0x00000000006e00cc in ExecInitNode (node=0x1ba8a18, estate=0x1c8efd8, eflags=16) at execProcnode.c:217 #6 0x00000000006d6abe in InitPlan (queryDesc=0x1c94aa8, eflags=16) at execMain.c:1046 #7 0x00000000006d58ad in standard_ExecutorStart (queryDesc=0x1c94aa8, eflags=16) at execMain.c:265 #8 0x00000000006d5649 in ExecutorStart (queryDesc=0x1c94aa8, eflags=0) at execMain.c:147 #9 0x00000000008c18d6 in PortalStart (portal=0x1c15608, params=0x0, eflags=0, snapshot=0x0) at pquery.c:520 #10 0x00000000008bbe1b in exec_simple_query (query_string=0x1ba6d78 "select 1+id,c2 from t_expr where id < 3;") at postgres.c:1106 #11 0x00000000008c0191 in PostgresMain (argc=1, argv=0x1bd4cb8, dbname=0x1bd4b20 "testdb", username=0x1ba3a98 "xdb") at postgres.c:4182 #12 0x000000000081e06c in BackendRun (port=0x1bc8ae0) at postmaster.c:4361 #13 0x000000000081d7df in BackendStartup (port=0x1bc8ae0) at postmaster.c:4033 #14 0x0000000000819bd9 in ServerLoop () at postmaster.c:1706 #15 0x000000000081948f in PostmasterMain (argc=1, argv=0x1ba1a50) at postmaster.c:1379 #16 0x0000000000742931 in main (argc=1, argv=0x1ba1a50) at main.c:228 执行跟踪,进入函数ExecBuildProjectionInfo (gdb) b ExecBuildProjectionInfo Breakpoint 1 at 0x6c5377: file execExpr.c, line 355. (gdb) c Continuing. Breakpoint 1, ExecBuildProjectionInfo (targetList=0x1c93498, econtext=0x1c883a8, slot=0x1c887c8, parent=0x1c88190, inputDesc=0x1c884a0) at execExpr.c:355 355 ProjectionInfo *projInfo = makeNode(ProjectionInfo); (gdb) 1.初始化 (gdb) n 357 ExprEvalStep scratch = {0}; (gdb) 360 projInfo->

Pi_exprContext = econtext

(gdb)

362projInfo- > pi_state.tag.type = T_ExprState

(gdb)

363 state = & projInfo- > pi_state

(gdb)

364 state- > expr = (Expr *) targetList

(gdb)

365 state- > parent = parent

(gdb)

366 state- > ext_params = NULL

(gdb)

368 state- > resultslot = slot

(gdb)

View related variables

(gdb) p * state

$1 = {tag = {type = T_ExprState}, flags = 0'\ 000mm, resnull = false, resvalue = 0, resultslot = 0x1c8f710, steps = 0x0

Evalfunc = 0x0, expr = 0x1cc7550, evalfunc_private = 0x0, steps_len = 0, steps_alloc = 0, parent = 0x1c8f1f0

Ext_params = 0x0, innermost_caseval = 0x0, innermost_casenull = 0x0, innermost_domainval = 0x0

Innermost_domainnull = 0x0}

Target list

(gdb) p targetList

$2 = (List *) 0x1cc7550

(gdb) p * targetList

$3 = {type = T_List, length = 2, head = 0x1cc7528, tail = 0x1cc75e0}

The first element is 1+id and the second element is c2

(gdb) p * (TargetEntry *) targetList- > head- > data.ptr_value

$7 = {xpr = {type = T_TargetEntry}, expr = 0x1c9a930, resno = 1, resname = 0xbcf498 "? column?", ressortgroupref = 0

Resorigtbl = 0, resorigcol = 0, resjunk = false}

(gdb) p * (OpExpr *) ((TargetEntry *) targetList- > head- > data.ptr_value)-> expr

$9 = {xpr = {type = T_OpExpr}, opno = 551, opfuncid = 177, opresulttype = 23, opretset = false, opcollid = 0

Inputcollid = 0, args = 0x1c9a878, location = 8}

(gdb) p * (Node *) targetList- > head- > next- > data.ptr_value

$10 = {type = T_TargetEntry}

(gdb) p * (TargetEntry *) targetList- > head- > next- > data.ptr_value

$11 = {xpr = {type = T_TargetEntry}, expr = 0x1c9aa40, resno = 2, resname = 0x1ba7a40 "c2", ressortgroupref = 0

Resorigtbl = 237600, resorigcol = 2, resjunk = false}

two。 Insert EEOP_*_FETCHSOME step (call ExecInitExprSlots) if necessary

(gdb)

371ExecInitExprSlots (state, (Node *) targetList)

The first step, opcode = 3, is EEOP_SCAN_FETCHSOME

(gdb) n

374foreach (lc, targetList)

(gdb) p * state

$13 = {tag = {type = T_ExprState}, flags = 0'\ 000mm, resnull = false, resvalue = 0, resultslot = 0x1c8f710

Steps = 0x1c8f868, evalfunc = 0x0, expr = 0x1cc7550, evalfunc_private = 0x0, steps_len = 1, steps_alloc = 16

Parent = 0x1c8f1f0, ext_params = 0x0, innermost_caseval = 0x0, innermost_casenull = 0x0, innermost_domainval = 0x0

Innermost_domainnull = 0x0}

(gdb) p state- > steps [0]

$14 = {opcode = 3, resvalue = 0x0, resnull = 0x0, d = {fetch = {last_var = 2, known_desc = 0x0}, var = {attnum = 2

Vartype = 0}, wholerow = {var = 0x2, first = false, slow = false, tupdesc = 0x0, junkFilter = 0x0}, assign_var = {

Resultnum = 2, attnum = 0}, assign_tmp = {resultnum = 2}, constval = {value = 2, isnull = false}, func = {

Finfo = 0x2, fcinfo_data = 0x0, fn_addr = 0x0, nargs = 0}, boolexpr = {anynull = 0x2, jumpdone = 0}, qualexpr = {

Jumpdone = 2}, jump = {jumpdone = 2}, nulltest_row = {argdesc = 0x2}, param = {paramid = 2, paramtype = 0}, cparam = {

Paramfunc = 0x2, paramarg = 0x0, paramid = 0, paramtype = 0}, casetest = {value = 0x2, isnull = 0x0}

Make_readonly = {value = 0x2, isnull = 0x0}, iocoerce = {finfo_out = 0x2, fcinfo_data_out = 0x0, finfo_in = 0x0

Fcinfo_data_in = 0x0}, sqlvaluefunction = {svf = 0x2}, nextvalueexpr = {seqid = 2, seqtypid = 0}, arrayexpr = {

Elemvalues = 0x2, elemnulls = 0x0, nelems = 0, elemtype = 0, elemlength = 0, elembyval = false, elemalign = 0'\ 000'

Multidims = false}, arraycoerce = {elemexprstate = 0x2, resultelemtype = 0, amstate = 0x0}, row = {tupdesc = 0x2

Elemvalues = 0x0, elemnulls = 0x0}, rowcompare_step = {finfo = 0x2, fcinfo_data = 0x0, fn_addr = 0x0, jumpnull = 0

Jumpdone = 0}, rowcompare_final = {rctype = ROWCOMPARE_LE}, minmax = {values = 0x2, nulls = 0x0, nelems = 0

Op = IS_GREATEST, finfo = 0x0, fcinfo_data = 0x0}, fieldselect = {fieldnum = 2, resulttype = 0, argdesc = 0x0}

Fieldstore = {fstore = 0x2, argdesc = 0x0, values = 0x0, nulls = 0x0, ncolumns = 0}, arrayref_subscript = {state = 0x2

Off = 0, isupper = false, jumpdone = 0}, arrayref = {state = 0x2}, domaincheck = {

Constraintname = 0x2, checkvalue = 0x0, checknull = 0x0, resulttype = 0}

Convert_rowtype = {convert = 0x2, indesc = 0x0, outdesc = 0x0, map = 0x0, initialized = false}, scalararrayop = {

Element_type = 2, useOr = false, typlen = 0, typbyval = false, typalign = 0'\ 000mm, finfo = 0x0, fcinfo_data = 0x0

Fn_addr = 0x0}, xmlexpr = {xexpr = 0x2, named_argvalue = 0x0, named_argnull = 0x0, argvalue = 0x0, argnull = 0x0}

Aggref = {astate = 0x2}, grouping_func = {parent = 0x2, clauses = 0x0}, window_func = {wfstate = 0x2}, subplan = {

Sstate = 0x2}, alternative_subplan = {asstate = 0x2}, agg_deserialize = {aggstate = 0x2, fcinfo_data = 0x0

Jumpnull = 0}, agg_strict_input_check = {nulls = 0x2, nargs = 0, jumpnull = 0}, agg_init_trans = {aggstate = 0x2

Pertrans = 0x0, aggcontext = 0x0, setno = 0, transno = 0, setoff = 0, jumpnull = 0}, agg_strict_trans_check = {

Aggstate = 0x2, setno = 0, transno = 0, setoff = 0, jumpnull = 0}, agg_trans = {aggstate = 0x2, pertrans = 0x0

Aggcontext = 0x0, setno = 0, transno = 0, setoff = 0}

(gdb)

3. Traverses the targetList, processing each column in the targetList (target column)

3.1. For "secure" Var, you only need to generate the EEOPASSIGN*_VAR step

3.2. For non-"safe" VAr, use the conventional method to handle column expressions, call the ExecInitExprRec function to process, and press the steps through ExprEvalPushStep

(gdb) n

376 TargetEntry * tle = lfirst_node (TargetEntry, lc)

(gdb)

377 Var * variable = NULL

(gdb)

378 AttrNumber attnum = 0

(gdb)

379 bool isSafeVar = false

(gdb)

389 if (tle- > expr! = NULL & &

(gdb)

390 IsA (tle- > expr, Var) &

(gdb)

389 if (tle- > expr! = NULL & &

(gdb)

415 if (isSafeVar)

(gdb) p * tle

$15 = {xpr = {type = T_TargetEntry}, expr = 0x1c9a930, resno = 1, resname = 0xbcf498 "? column?", ressortgroupref = 0

Resorigtbl = 0, resorigcol = 0, resjunk = false}

(gdb) n

452 ExecInitExprRec (tle- > expr, state

(gdb)

Enter the ExecInitExprRec,Node node as OpExpr, and perform the ExprEvalPushStep push step

(gdb) step

ExecInitExprRec (node=0x1c9a930, state=0x1c8f7d8, resv=0x1c8f7e0, resnull=0x1c8f7dd) at execExpr.c:645

645 ExprEvalStep scratch = {0}

(gdb) n

648 check_stack_depth ()

(gdb)

651 Assert (resv! = NULL & & resnull! = NULL)

(gdb)

652 scratch.resvalue = resv

(gdb)

653 scratch.resnull = resnull

(gdb)

656 switch (nodeTag (node))

(gdb)

891 OpExpr * op = (OpExpr *) node

(gdb) p * node

$16 = {type = T_OpExpr}

(gdb) n

893 ExecInitFunc & scratch, node

(gdb)

896 ExprEvalPushStep (state, & scratch)

(gdb)

897 break

(gdb)

2122}

(gdb)

ExecBuildProjectionInfo (targetList=0x1cc7550, econtext=0x1c8f408, slot=0x1c8f710, parent=0x1c8f1f0

InputDesc=0x7f8386bb6ab8) at execExpr.c:459

459 if (get_typlen (exprType ((Node *) tle- > expr)) =-1)

(gdb)

462 scratch.opcode = EEOP_ASSIGN_TMP

(gdb)

After the call to ExecInitExprRec is completed, two additional steps have been added:

1.opcode = 6, that is EEOP_SCAN_VAR

2.opcode = 18, that is EEOP_FUNCEXPR_STRICT

(gdb) p * state

$17 = {tag = {type = T_ExprState}, flags = 0'\ 000mm, resnull = false, resvalue = 0, resultslot = 0x1c8f710

Steps = 0x1c8f868, evalfunc = 0x0, expr = 0x1cc7550, evalfunc_private = 0x0, steps_len = 3, steps_alloc = 16

Parent = 0x1c8f1f0, ext_params = 0x0, innermost_caseval = 0x0, innermost_casenull = 0x0, innermost_domainval = 0x0

Innermost_domainnull = 0x0}

(gdb) p state- > steps [1]

$18 = {opcode = 6, resvalue = 0x1c8fd00, resnull = 0x1c90019, d = {fetch = {last_var = 0, known_desc = 0x0}, var = {

Attnum = 0, vartype = 23}, wholerow = {var = 0x1700000000, first = false, slow = false, tupdesc = 0x0

JunkFilter = 0x0}, assign_var = {resultnum = 0, attnum = 23}, assign_tmp = {resultnum = 0}, constval = {

Value = 98784247808, isnull = false}, func = {finfo = 0x1700000000, fcinfo_data = 0x0, fn_addr = 0x0, nargs = 0}

Boolexpr = {anynull = 0x1700000000, jumpdone = 0}, qualexpr = {jumpdone = 0}, jump = {jumpdone = 0}, nulltest_row = {

Argdesc = 0x1700000000}, param = {paramid = 0, paramtype = 23}, cparam = {paramfunc = 0x1700000000, paramarg = 0x0

Paramid = 0, paramtype = 0}, casetest = {value = 0x1700000000, isnull = 0x0}, make_readonly = {value = 0x1700000000

Isnull = 0x0}, iocoerce = {finfo_out = 0x1700000000, fcinfo_data_out = 0x0, finfo_in = 0x0, fcinfo_data_in = 0x0}

Sqlvaluefunction = {svf = 0x1700000000}, nextvalueexpr = {seqid = 0, seqtypid = 23}, arrayexpr = {

Elemvalues = 0x1700000000, elemnulls = 0x0, nelems = 0, elemtype = 0, elemlength = 0, elembyval = false

Elemalign = 0'\ 000mm, multidims = false}, arraycoerce = {elemexprstate = 0x1700000000, resultelemtype = 0

Amstate = 0x0}, row = {tupdesc = 0x1700000000, elemvalues = 0x0, elemnulls = 0x0}, rowcompare_step = {

Finfo = 0x1700000000, fcinfo_data = 0x0, fn_addr = 0x0, jumpnull = 0, jumpdone = 0}, rowcompare_final = {rctype = 0}

Minmax = {values = 0x1700000000, nulls = 0x0, nelems = 0, op = IS_GREATEST, finfo = 0x0, fcinfo_data = 0x0}

Fieldselect = {fieldnum = 0, resulttype = 23, argdesc = 0x0}, fieldstore = {fstore = 0x1700000000, argdesc = 0x0

Values = 0x0, nulls = 0x0, ncolumns = 0}, arrayref_subscript = {state = 0x1700000000, off = 0, isupper = false

Jumpdone = 0}, arrayref = {state = 0x1700000000}, domaincheck = {

Constraintname = 0x1700000000, checkvalue = 0x0, checknull = 0x0

Resulttype = 0}, convert_rowtype = {convert = 0x1700000000, indesc = 0x0, outdesc = 0x0, map = 0x0

Initialized = false}, scalararrayop = {element_type = 0, useOr = 23, typlen = 0, typbyval = false

Typalign = 0'\ 000mm, finfo = 0x0, fcinfo_data = 0x0, fn_addr = 0x0}, xmlexpr = {xexpr = 0x1700000000

Named_argvalue = 0x0, named_argnull = 0x0, argvalue = 0x0, argnull = 0x0}, aggref = {astate = 0x1700000000}

Grouping_func = {parent = 0x1700000000, clauses = 0x0}, window_func = {wfstate = 0x1700000000}, subplan = {

Sstate = 0x1700000000}, alternative_subplan = {asstate = 0x1700000000}, agg_deserialize = {aggstate = 0x1700000000

Fcinfo_data = 0x0, jumpnull = 0}, agg_strict_input_check = {nulls = 0x1700000000, nargs = 0, jumpnull = 0}

Agg_init_trans = {aggstate = 0x1700000000, pertrans = 0x0, aggcontext = 0x0, setno = 0, transno = 0, setoff = 0

Jumpnull = 0}, agg_strict_trans_check = {aggstate = 0x1700000000, setno = 0, transno = 0, setoff = 0, jumpnull = 0}

-Type to continue, or q to quit

Agg_trans = {aggstate = 0x1700000000, pertrans = 0x0, aggcontext = 0x0, setno = 0, transno = 0, setoff = 0}

(gdb) p state- > steps [2]

$19 = {opcode = 18, resvalue = 0x1c8f7e0, resnull = 0x1c8f7dd, d = {fetch = {last_var = 29949056, known_desc = 0x1c8fcd8}

Var = {attnum = 29949056, vartype = 0}, wholerow = {var = 0x1c8fc80, first = 216,252

Tupdesc = 0x93d60c, junkFilter = 0x2}, assign_var = {resultnum = 29949056, attnum = 0}, assign_tmp = {

Resultnum = 29949056}, constval = {value = 29949056, isnull = 29949056}, func = {finfo = 0x1c8fc80

Fcinfo_data = 0x1c8fcd8, fn_addr = 0x93d60c, nargs = 2}, boolexpr = {anynull = 0x1c8fc80

Jumpdone = 29949144}, qualexpr = {jumpdone = 29949056}, jump = {jumpdone = 29949056}, nulltest_row = {

Argdesc = 0x1c8fc80}, param = {paramid = 29949056, paramtype = 0}, cparam = {paramfunc = 0x1c8fc80

Paramarg = 0x1c8fcd8, paramid = 9688588, paramtype = 0}, casetest = {value = 0x1c8fc80, isnull = 0x1c8fcd8}

Make_readonly = {value = 0x1c8fc80, isnull = 0x1c8fcd8}, iocoerce = {finfo_out = 0x1c8fc80

Fcinfo_data_out = 0x1c8fcd8, finfo_in = 0x93d60c, fcinfo_data_in = 0x2}, sqlvaluefunction = {

Svf = 0x1c8fc80}, nextvalueexpr = {seqid = 29949056, seqtypid = 0}, arrayexpr = {elemvalues = 0x1c8fc80

Elemnulls = 0x1c8fcd8, nelems = 9688588, elemtype = 0, elemlength = 2, elembyval = false, elemalign = 0'\ 000'

Multidims = false}, arraycoerce = {elemexprstate = 0x1c8fc80, resultelemtype = 29949144

Amstate = 0x93d60c}, row = {tupdesc = 0x1c8fc80, elemvalues = 0x1c8fcd8, elemnulls = 0x93d60c}

Rowcompare_step = {finfo = 0x1c8fc80, fcinfo_data = 0x1c8fcd8, fn_addr = 0x93d60c, jumpnull = 2

Jumpdone = 0}, rowcompare_final = {rctype = 29949056}, minmax = {values = 0x1c8fc80, nulls = 0x1c8fcd8

Nelems = 9688588, op = IS_GREATEST, finfo = 0x2, fcinfo_data = 0x0}, fieldselect = {fieldnum =-896, resulttype = 0

Argdesc = 0x1c8fcd8}, fieldstore = {fstore = 0x1c8fc80, argdesc = 0x1c8fcd8, values = 0x93d60c, nulls = 0x2

Ncolumns = 0}, arrayref_subscript = {state = 0x1c8fc80, off = 29949144, isupper = false, jumpdone = 9688588}

Arrayref = {state = 0x1c8fc80}, domaincheck = {constraintname = 0x1c8fc80 "\ f stories", checkvalue = 0x1c8fcd8

Checknull = 0x93d60c, resulttype = 2}, convert_rowtype = {convert = 0x1c8fc80, indesc = 0x1c8fcd8

Outdesc = 0x93d60c, map = 0x2, initialized = false}, scalararrayop = {element_type = 29949056

UseOr = false, typlen = 0, typbyval = 216,216,374, finfo = 0x93d60c, fcinfo_data = 0x2

Fn_addr = 0x0}, xmlexpr = {xexpr = 0x1c8fc80, named_argvalue = 0x1c8fcd8, named_argnull = 0x93d60c

Argvalue = 0x2, argnull = 0x0}, aggref = {astate = 0x1c8fc80}, grouping_func = {parent = 0x1c8fc80

Clauses = 0x1c8fcd8}, window_func = {wfstate = 0x1c8fc80}, subplan = {sstate = 0x1c8fc80}, alternative_subplan = {

Asstate = 0x1c8fc80}, agg_deserialize = {aggstate = 0x1c8fc80, fcinfo_data = 0x1c8fcd8, jumpnull = 9688588}

-Type to continue, or q to quit

Agg_strict_input_check = {nulls = 0x1c8fc80, nargs = 29949144, jumpnull = 0}, agg_init_trans = {aggstate = 0x1c8fc80

Pertrans = 0x1c8fcd8, aggcontext = 0x93d60c, setno = 2, transno = 0, setoff = 0, jumpnull = 0}

Agg_strict_trans_check = {aggstate = 0x1c8fc80, setno = 29949144, transno = 0, setoff = 9688588, jumpnull = 0}

Agg_trans = {aggstate = 0x1c8fc80, pertrans = 0x1c8fcd8, aggcontext = 0x93d60c, setno = 2, transno = 0

Setoff = 0}

(gdb)

Press the number of the column of the expression, opcode = 14, that is, EEOP_ASSIGN_TMP

(gdb) n

463 scratch.d.assign_tmp.resultnum = tle- > resno-1

(gdb)

464 ExprEvalPushStep (state, & scratch)

(gdb)

374foreach (lc, targetList)

(gdb) p * state

$20 = {tag = {type = T_ExprState}, flags = 0'\ 000mm, resnull = false, resvalue = 0, resultslot = 0x1c8f710

Steps = 0x1c8f868, evalfunc = 0x0, expr = 0x1cc7550, evalfunc_private = 0x0, steps_len = 4, steps_alloc = 16

Parent = 0x1c8f1f0, ext_params = 0x0, innermost_caseval = 0x0, innermost_casenull = 0x0, innermost_domainval = 0x0

Innermost_domainnull = 0x0}

(gdb) p state- > steps [3]

$21 = {opcode = 14, resvalue = 0x0, resnull = 0x0, d = {fetch = {last_var = 0, known_desc = 0x0}, var = {attnum = 0

Vartype = 0}, wholerow = {var = 0x0, first = false, slow = false, tupdesc = 0x0, junkFilter = 0x0}, assign_var = {

Resultnum = 0, attnum = 0}, assign_tmp = {resultnum = 0}, constval = {value = 0, isnull = false}, func = {

Finfo = 0x0, fcinfo_data = 0x0, fn_addr = 0x0, nargs = 0}, boolexpr = {anynull = 0x0, jumpdone = 0}, qualexpr = {

Jumpdone = 0}, jump = {jumpdone = 0}, nulltest_row = {argdesc = 0x0}, param = {paramid = 0, paramtype = 0}, cparam = {

Paramfunc = 0x0, paramarg = 0x0, paramid = 0, paramtype = 0}, casetest = {value = 0x0, isnull = 0x0}

Make_readonly = {value = 0x0, isnull = 0x0}, iocoerce = {finfo_out = 0x0, fcinfo_data_out = 0x0, finfo_in = 0x0

Fcinfo_data_in = 0x0}, sqlvaluefunction = {svf = 0x0}, nextvalueexpr = {seqid = 0, seqtypid = 0}, arrayexpr = {

Elemvalues = 0x0, elemnulls = 0x0, nelems = 0, elemtype = 0, elemlength = 0, elembyval = false, elemalign = 0'\ 000'

Multidims = false}, arraycoerce = {elemexprstate = 0x0, resultelemtype = 0, amstate = 0x0}, row = {tupdesc = 0x0

Elemvalues = 0x0, elemnulls = 0x0}, rowcompare_step = {finfo = 0x0, fcinfo_data = 0x0, fn_addr = 0x0, jumpnull = 0

Jumpdone = 0}, rowcompare_final = {rctype = 0}, minmax = {values = 0x0, nulls = 0x0, nelems = 0, op = IS_GREATEST

Finfo = 0x0, fcinfo_data = 0x0}, fieldselect = {fieldnum = 0, resulttype = 0, argdesc = 0x0}, fieldstore = {

Fstore = 0x0, argdesc = 0x0, values = 0x0, nulls = 0x0, ncolumns = 0}, arrayref_subscript = {state = 0x0, off = 0

Isupper = false, jumpdone = 0}, arrayref = {state = 0x0}, domaincheck = {constraintname = 0x0, checkvalue = 0x0

Checknull = 0x0, resulttype = 0}, convert_rowtype = {convert = 0x0, indesc = 0x0, outdesc = 0x0, map = 0x0

Initialized = false}, scalararrayop = {element_type = 0, useOr = false, typlen = 0, typbyval = false

Typalign = 0'\ 000mm, finfo = 0x0, fcinfo_data = 0x0, fn_addr = 0x0}, xmlexpr = {xexpr = 0x0, named_argvalue = 0x0

Named_argnull = 0x0, argvalue = 0x0, argnull = 0x0}, aggref = {astate = 0x0}, grouping_func = {parent = 0x0

Clauses = 0x0}, window_func = {wfstate = 0x0}, subplan = {sstate = 0x0}, alternative_subplan = {asstate = 0x0}

Agg_deserialize = {aggstate = 0x0, fcinfo_data = 0x0, jumpnull = 0}, agg_strict_input_check = {nulls = 0x0, nargs = 0

Jumpnull = 0}, agg_init_trans = {aggstate = 0x0, pertrans = 0x0, aggcontext = 0x0, setno = 0, transno = 0

Setoff = 0, jumpnull = 0}, agg_strict_trans_check = {aggstate = 0x0, setno = 0, transno = 0, setoff = 0

Jumpnull = 0}, agg_trans = {aggstate = 0x0, pertrans = 0x0, aggcontext = 0x0, setno = 0, transno = 0, setoff = 0}

(gdb)

Proceed to the next column, which is a "security" column, press the EEOP_ASSIGN_SCAN_VAR step

(gdb) n

376 TargetEntry * tle = lfirst_node (TargetEntry, lc)

(gdb)

377 Var * variable = NULL

(gdb) p * tle

$22 = {xpr = {type = T_TargetEntry}, expr = 0x1c9aa40, resno = 2, resname = 0x1ba7a40 "c2", ressortgroupref = 0

Resorigtbl = 237600, resorigcol = 2, resjunk = false}

(gdb) n

378 AttrNumber attnum = 0

(gdb)

379 bool isSafeVar = false

(gdb)

389 if (tle- > expr! = NULL & &

(gdb)

390 IsA (tle- > expr, Var) &

(gdb)

389 if (tle- > expr! = NULL & &

(gdb)

391 ((Var *) tle- > expr)-> varattno > 0)

(gdb)

390 IsA (tle- > expr, Var) &

(gdb)

394 variable = (Var *) tle- > expr

(gdb)

395 attnum = variable- > varattno

(gdb)

397 if (inputDesc = = NULL)

(gdb)

399 else if (attnum natts)

(gdb)

401 Form_pg_attribute attr = TupleDescAttr (inputDesc, attnum-1)

(gdb)

If (! attr- > attisdropped & & variable- > vartype = = attr- > atttypid)

(gdb)

410 isSafeVar = true

(gdb)

415 if (isSafeVar)

(gdb)

418 switch (variable- > varno)

(gdb)

434 scratch.opcode = EEOP_ASSIGN_SCAN_VAR

(gdb)

435 break

(gdb)

438 scratch.d.assign_var.attnum = attnum-1

(gdb)

439 scratch.d.assign_var.resultnum = tle- > resno-1

(gdb)

440 ExprEvalPushStep (state, & scratch)

(gdb) p * state

$23 = {tag = {type = T_ExprState}, flags = 0'\ 000mm, resnull = false, resvalue = 0, resultslot = 0x1c8f710

Steps = 0x1c8f868, evalfunc = 0x0, expr = 0x1cc7550, evalfunc_private = 0x0, steps_len = 4, steps_alloc = 16

Parent = 0x1c8f1f0, ext_params = 0x0, innermost_caseval = 0x0, innermost_casenull = 0x0, innermost_domainval = 0x0

Innermost_domainnull = 0x0}

(gdb) n

374foreach (lc, targetList)

(gdb) p * state

$24 = {tag = {type = T_ExprState}, flags = 0'\ 000mm, resnull = false, resvalue = 0, resultslot = 0x1c8f710

Steps = 0x1c8f868, evalfunc = 0x0, expr = 0x1cc7550, evalfunc_private = 0x0, steps_len = 5, steps_alloc = 16

Parent = 0x1c8f1f0, ext_params = 0x0, innermost_caseval = 0x0, innermost_casenull = 0x0, innermost_domainval = 0x0

Innermost_domainnull = 0x0}

(gdb) p state- > steps [4]

$25 = {opcode = 13, resvalue = 0x0, resnull = 0x0, d = {fetch = {last_var = 1, known_desc = 0x0}, var = {attnum = 1

Vartype = 1}, wholerow = {var = 0x100000001, first = false, slow = false, tupdesc = 0x0, junkFilter = 0x0}

Assign_var = {resultnum = 1, attnum = 1}, assign_tmp = {resultnum = 1}, constval = {value = 4294967297

Isnull = false}, func = {finfo = 0x100000001, fcinfo_data = 0x0, fn_addr = 0x0, nargs = 0}, boolexpr = {

Anynull = 0x100000001, jumpdone = 0}, qualexpr = {jumpdone = 1}, jump = {jumpdone = 1}, nulltest_row = {

Argdesc = 0x100000001}, param = {paramid = 1, paramtype = 1}, cparam = {paramfunc = 0x100000001, paramarg = 0x0

Paramid = 0, paramtype = 0}, casetest = {value = 0x100000001, isnull = 0x0}, make_readonly = {value = 0x100000001

Isnull = 0x0}, iocoerce = {finfo_out = 0x100000001, fcinfo_data_out = 0x0, finfo_in = 0x0, fcinfo_data_in = 0x0}

Sqlvaluefunction = {svf = 0x100000001}, nextvalueexpr = {seqid = 1, seqtypid = 1}, arrayexpr = {

Elemvalues = 0x100000001, elemnulls = 0x0, nelems = 0, elemtype = 0, elemlength = 0, elembyval = false

Elemalign = 0'\ 000mm, multidims = false}, arraycoerce = {elemexprstate = 0x100000001, resultelemtype = 0

Amstate = 0x0}, row = {tupdesc = 0x100000001, elemvalues = 0x0, elemnulls = 0x0}, rowcompare_step = {

Finfo = 0x100000001, fcinfo_data = 0x0, fn_addr = 0x0, jumpnull = 0, jumpdone = 0}, rowcompare_final = {

Rctype = ROWCOMPARE_LT}, minmax = {values = 0x100000001, nulls = 0x0, nelems = 0, op = IS_GREATEST, finfo = 0x0

Fcinfo_data = 0x0}, fieldselect = {fieldnum = 1, resulttype = 1, argdesc = 0x0}, fieldstore = {fstore = 0x100000001

Argdesc = 0x0, values = 0x0, nulls = 0x0, ncolumns = 0}, arrayref_subscript = {state = 0x100000001, off = 0

Isupper = false, jumpdone = 0}, arrayref = {state = 0x100000001}, domaincheck = {

Constraintname = 0x100000001, checkvalue = 0x0, checknull = 0x0, resulttype = 0}

Convert_rowtype = {convert = 0x100000001, indesc = 0x0, outdesc = 0x0, map = 0x0, initialized = false}

Scalararrayop = {element_type = 1, useOr = true, typlen = 0, typbyval = false, typalign = 0'\ 000mm, finfo = 0x0

Fcinfo_data = 0x0, fn_addr = 0x0}, xmlexpr = {xexpr = 0x100000001, named_argvalue = 0x0, named_argnull = 0x0

Argvalue = 0x0, argnull = 0x0}, aggref = {astate = 0x100000001}, grouping_func = {parent = 0x100000001

Clauses = 0x0}, window_func = {wfstate = 0x100000001}, subplan = {sstate = 0x100000001}, alternative_subplan = {

Asstate = 0x100000001}, agg_deserialize = {aggstate = 0x100000001, fcinfo_data = 0x0, jumpnull = 0}

Agg_strict_input_check = {nulls = 0x100000001, nargs = 0, jumpnull = 0}, agg_init_trans = {aggstate = 0x100000001

Pertrans = 0x0, aggcontext = 0x0, setno = 0, transno = 0, setoff = 0, jumpnull = 0}, agg_strict_trans_check = {

Aggstate = 0x100000001, setno = 0, transno = 0, setoff = 0, jumpnull = 0}, agg_trans = {aggstate = 0x100000001

-Type to continue, or q to quit

Pertrans = 0x0, aggcontext = 0x0, setno = 0, transno = 0, setoff = 0}}

(gdb)

4. Press in EEOP_DONE step

(gdb) n

468 scratch.opcode = EEOP_DONE

(gdb)

469 ExprEvalPushStep (state, & scratch)

(gdb)

471 ExecReadyExpr (state)

(gdb) p state- > steps [5]

$26 = {opcode = 0, resvalue = 0x0, resnull = 0x0, d = {fetch = {last_var = 1, known_desc = 0x0}, var = {attnum = 1