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| author | Tomas Vondra <tomas.vondra@postgresql.org> | 2019-01-19 23:48:16 +0100 |
|---|---|---|
| committer | Tomas Vondra <tomas.vondra@postgresql.org> | 2019-01-20 00:22:14 +0100 |
| commit | 31f3817402da736b29014ace470cf70aeb126ac5 (patch) | |
| tree | ab02bcacacdb944f47996f10435a94c9f0258543 /src/backend/parser/parse_agg.c | |
| parent | d6ef7fe75c1fb7ccc4ad8e3dd38d4e84d6fe9b9f (diff) | |
| download | postgresql-31f3817402da736b29014ace470cf70aeb126ac5.tar.gz postgresql-31f3817402da736b29014ace470cf70aeb126ac5.zip | |
Allow COPY FROM to filter data using WHERE conditions
Extends the COPY FROM command with a WHERE condition, which allows doing
various types of filtering while importing the data (random sampling,
condition on a data column, etc.). Until now such filtering required
either preprocessing of the input data, or importing all data and then
filtering in the database. COPY FROM ... WHERE is an easy-to-use and
low-overhead alternative for most simple cases.
Author: Surafel Temesgen
Reviewed-by: Tomas Vondra, Masahiko Sawada, Lim Myungkyu
Discussion: https://www.postgresql.org/message-id/flat/CALAY4q_DdpWDuB5-Zyi-oTtO2uSk8pmy+dupiRe3AvAc++1imA@mail.gmail.com
Diffstat (limited to 'src/backend/parser/parse_agg.c')
| -rw-r--r-- | src/backend/parser/parse_agg.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c index bd6201e50a7..669fe82c48a 100644 --- a/src/backend/parser/parse_agg.c +++ b/src/backend/parser/parse_agg.c @@ -523,6 +523,14 @@ check_agglevels_and_constraints(ParseState *pstate, Node *expr) break; + case EXPR_KIND_COPY_WHERE: + if (isAgg) + err = _("aggregate functions are not allowed in COPY FROM WHERE conditions"); + else + err = _("grouping operations are not allowed in COPY FROM WHERE conditions"); + + break; + /* * There is intentionally no default: case here, so that the * compiler will warn if we add a new ParseExprKind without @@ -902,6 +910,9 @@ transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc, case EXPR_KIND_CALL_ARGUMENT: err = _("window functions are not allowed in CALL arguments"); break; + case EXPR_KIND_COPY_WHERE: + err = _("window functions are not allowed in COPY FROM WHERE conditions"); + break; /* * There is intentionally no default: case here, so that the |