/* parse */
pg_parse_query
raw_parser
/* analyze and rewrite */
pg_analyze_and_rewrite_fixedparams
parse_analyze_fixedparams
pg_rewrite_query
/* plan */
pg_plan_queries
/* execute */
PortalStart
ExecutorStart
PortalRun - PortalRunSelect
ExecutorRun
PortalDrop
ExecutorFinish
ExecutorEnd
/* 1. Parse */
pg_parse_query // Parse by Bison(gram.y), support multi queries
raw_parser
/* 2. Analyze & Rewrite */
pg_analyze_and_rewrite_fixedparams // analyze and rewrite RawStmt, RawStmt -> Query
query = parse_analyze_fixedparams // Perform parse analysis. RawStmt -> Query
transformTopLevelStmt - transformOptionalSelectInto - transformStmt
transformSelectStmt
Query *qry = makeNode(Query);
transform***Clause
querytree_list = pg_rewrite_query // Rewrite the queries, as necessary. Query -> List(Query)
QueryRewrite // don't rewrite utilities
/* 3. Plan */
pg_plan_queries // querytree_list -> plantree_list(PlannedStmt), plan just for dml(select, insert, update, delete, merge)
pg_plan_query - planner - standard_planner - subquery_planner
/* primary planning entry point (may recurse for subqueries) */
root = subquery_planner(glob, parse, NULL, false, tuple_fraction);
/* Select best Path and turn it into a Plan */
final_rel = fetch_upper_rel(root, UPPERREL_FINAL, NULL);
best_path = get_cheapest_fractional_path(final_rel, tuple_fraction);
PlannedStmt.planTree = create_plan(root, best_path);
/* 4. Portal */
CreatePortal
PortalDefineQuery // portal->stmts = plantree_list;
PortalStart // Prepare a portal for execution. params, strategy, queryDesc
queryDesc = CreateQueryDesc
ExecutorStart(queryDesc, myeflags); // prepare the plan for execution
standard_ExecutorStart
portal->queryDesc = queryDesc;
portal->status = PORTAL_READY;
PortalSetResultFormat
PortalRun - PortalRunSelect
/* 5. Executor */
ExecutorRun - tandard_ExecutorRun - ExecutePlan // Processes the query plan until retrieved 'numberTuples' tuples
ExecProcNode - ExecSeqScan
ExecScan - ExecScanFetch - SeqNext // executor module
/* Access + Storage*/
table_scan_getnextslot - heap_getnextslot - heapgettup_pagemode
heapgetpage
ReadBufferExtended
ReadBuffer_common
BufferAlloc
InitBufferTag
LWLockAcquire(newPartitionLock, LW_SHARED);
existing_buf_id = BufTableLookup(&newTag, newHash);
LockBuffer(buffer, BUFFER_LOCK_SHARE);
BufferGetPage - BufferGetBlock
return (Block) (BufferBlocks + ((Size) (buffer - 1)) * BLCKSZ);
for (lineoff = FirstOffsetNumber; lineoff <= lines; lineoff++)
PageGetItemId // Returns an item identifier of a page.
return &((PageHeader) page)->pd_linp[offsetNumber - 1];
PageGetItem // Retrieves an item on the given page.
return (Item) (((char *) page) + ItemIdGetOffset(itemId));
// True if heap tuple satisfies a time qual
HeapTupleSatisfiesVisibility - HeapTupleSatisfiesMVCC
HeapCheckForSerializableConflictOut
scan->rs_vistuples[ntup++] = lineoff;
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
return slot;
ExecProject
PortalDrop