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postgresqlpostgresql-9.3

How could I get table name from OID in postgresql?

I tried to use function get_rel_name(OID) to get table name, but the output is NULL, could anyone tell me why and how can I get the table name in backend of postgresql? thanks. 

for (rti = 1; rti < root->simple_rel_array_size; rti++)
{
    RelOptInfo *rel = root->simple_rel_array[rti];
    printf("rel->relid=%d %s \n",rel->relid, get_rel_name(rel->relid));
}

In src/backend/optimizer/path/costsize.c in the function below. 

void 
cost_seqscan(Path *path, PlannerInfo *root,
         RelOptInfo *baserel, ParamPathInfo *param_info)
Solution

  • I got it, it should be 

    for (rti = 1; rti < root->simple_rel_array_size; rti++)
{
    RangeTblEntry *rte=root->simple_rte_array[rti];
    printf("table name is %s \n",get_rel_name(rte->relid));
}