vamsi krishna wrote:
> hi,
> i want to know how CREATE table (creating a
> relation)
See DefineRelation() in backend/commands/tablecmds.c, and the routines
it calls.
> also i want to know how postgres parser the
> input(create table) and how is this connected to the
> create table source code files.
See the CreateStmt production in backend/parser/gram.y (circa line 1509
in current sources). CREATE TABLE is a utility statement, so a
high-level view of the processing is:
- the query string is scanned (scan.l) and parsed (gram.y), producing a
raw parse tree
- in the analysis phase, transformCreateStmt() does a few simple
transformations of the raw parse tree and produces a Query representing
the CREATE TABLE utility statement
- ProcessUtility() in backend/tcop/utility.c invokes DefineRelation()
-Neil