Skip to content

Do not wrap postgres_query SQL unless necessary #620

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
staticlibs merged 1 commit into from
Oct 15, 2026
Merged

Do not wrap postgres_query SQL unless necessary #620

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 3 additions & 1 deletion src/postgres_query.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -205,7 +205,9 @@ static unique_ptr<FunctionData> PGQueryBind(ClientContext &context, TableFunctio
auto converted_type = PostgresUtils::TypeToLogicalType(nullptr, nullptr, type_config, type_data, postgres_type);
result->postgres_types.push_back(postgres_type);
return_types.emplace_back(converted_type);
names.emplace_back(PQfname(describe_prepared, c));
char *name_ptr = PQfname(describe_prepared, c);
string name = name_ptr ? name_ptr : StringUtil::Format("unnamed_%llu", c);
names.emplace_back(name);
}
int nparams = PQnparams(describe_prepared);
if (nparams != param_values.size()) {
Expand Down
79 changes: 46 additions & 33 deletions src/postgres_scanner.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -189,55 +189,64 @@ static bool ContainsCastToVarchar(const PostgresType &type) {
return false;
}

static void PostgresInitInternal(ClientContext &context, const PostgresBindData *bind_data_p,
PostgresLocalState &lstate, idx_t task_min, idx_t task_max) {
D_ASSERT(bind_data_p);
D_ASSERT(task_min <= task_max);

auto bind_data = (const PostgresBindData *)bind_data_p;

static string WriteColumnNames(const PostgresBindData &bind_data, const PostgresLocalState &lstate,
bool &col_names_required) {
string col_names;
col_names_required = bind_data.names.size() != lstate.column_ids.size();
for (auto &column_id : lstate.column_ids) {
if (!col_names.empty()) {
col_names += ", ";
}
if (column_id == COLUMN_IDENTIFIER_ROW_ID) {
if (bind_data->table_name.empty() || !bind_data->emit_ctid) {
if (bind_data.table_name.empty() || !bind_data.emit_ctid) {
// count(*) over postgres_query
col_names += "NULL";
} else {
col_names += "ctid";
}
col_names_required = true;
} else {
col_names += PostgresUtils::WriteIdentifier(bind_data->names[column_id]);
if (bind_data->postgres_types[column_id].info == PostgresTypeAnnotation::CAST_TO_VARCHAR) {
col_names += PostgresUtils::WriteIdentifier(bind_data.names[column_id]);
if (bind_data.postgres_types[column_id].info == PostgresTypeAnnotation::CAST_TO_VARCHAR) {
col_names += "::VARCHAR";
} else if (bind_data->types[column_id].id() == LogicalTypeId::LIST) {
if (bind_data->postgres_types[column_id].info != PostgresTypeAnnotation::STANDARD) {
col_names_required = true;
} else if (bind_data.types[column_id].id() == LogicalTypeId::LIST) {
if (bind_data.postgres_types[column_id].info != PostgresTypeAnnotation::STANDARD) {
continue;
}
if (bind_data->postgres_types[column_id].children[0].info == PostgresTypeAnnotation::CAST_TO_VARCHAR) {
if (bind_data.postgres_types[column_id].children[0].info == PostgresTypeAnnotation::CAST_TO_VARCHAR) {
col_names += "::VARCHAR[]";
col_names_required = true;
}
} else {
if (ContainsCastToVarchar(bind_data->postgres_types[column_id])) {
if (ContainsCastToVarchar(bind_data.postgres_types[column_id])) {
throw NotImplementedException("Error reading table \"%s\" - cast to varchar not implemented for "
"composite column \"%s\" (type %s)",
bind_data->table_name, bind_data->names[column_id],
bind_data->types[column_id].ToString());
bind_data.table_name, bind_data.names[column_id],
bind_data.types[column_id].ToString());
}
}
}
}
return col_names;
}

string filter_string =
PostgresFilterPushdown::TransformFilters(lstate.column_ids, lstate.filters, bind_data->names);
static void PostgresInitInternal(ClientContext &context, const PostgresBindData *bind_data_p,
PostgresLocalState &lstate, idx_t task_min, idx_t task_max) {
D_ASSERT(bind_data_p);
D_ASSERT(task_min <= task_max);

auto bind_data = bind_data_p->Cast<PostgresBindData>();

bool col_names_required = false;
string col_names = WriteColumnNames(bind_data, lstate, col_names_required);
string filter_string = PostgresFilterPushdown::TransformFilters(lstate.column_ids, lstate.filters, bind_data.names);

string filter;

lstate.exec = false;
lstate.done = false;
if (bind_data->pages_approx > 0) {
if (bind_data.pages_approx > 0) {
filter = StringUtil::Format("WHERE ctid BETWEEN '(%d,0)'::tid AND '(%d,0)'::tid", task_min, task_max);
}
if (!filter_string.empty()) {
Expand All @@ -248,24 +257,28 @@ static void PostgresInitInternal(ClientContext &context, const PostgresBindData
}
filter += filter_string;
}
string query;
if (bind_data->table_name.empty()) {
D_ASSERT(!bind_data->sql.empty());
query =
StringUtil::Format(R"(SELECT %s FROM (%s) AS __unnamed_subquery %s)", col_names, bind_data->sql, filter);

string query;
if (bind_data.table_name.empty()) {
D_ASSERT(!bind_data.sql.empty());
if (col_names_required) {
query =
StringUtil::Format("SELECT %s FROM (%s) AS __unnamed_subquery %s", col_names, bind_data.sql, filter);
} else if (!filter.empty()) {
query = StringUtil::Format("%s %s", bind_data.sql, filter);
} else {
query = bind_data.sql;
}
} else {
query = StringUtil::Format(R"(SELECT %s FROM %s.%s %s)", col_names,
PostgresUtils::WriteIdentifier(bind_data->schema_name),
PostgresUtils::WriteIdentifier(bind_data->table_name), filter);
query = StringUtil::Format("SELECT %s FROM %s.%s %s", col_names,
PostgresUtils::WriteIdentifier(bind_data.schema_name),
PostgresUtils::WriteIdentifier(bind_data.table_name), filter);
}
if (!bind_data->limit_clause.empty()) {
query += bind_data->limit_clause;
if (!bind_data.limit_clause.empty()) {
query += bind_data.limit_clause;
}
if (!(bind_data->use_text_protocol || bind_data->query_mode == PostgresQueryMode::PLAIN_QUERY_BINARY)) {
query = StringUtil::Format(R"(COPY (%s) TO STDOUT (FORMAT "binary");)", query);
} else {
query += ";";
if (!(bind_data.use_text_protocol || bind_data.query_mode == PostgresQueryMode::PLAIN_QUERY_BINARY)) {
query = StringUtil::Format("COPY (%s) TO STDOUT (FORMAT \"binary\");", query);
}
lstate.sql = std::move(query);
}
Expand Down
114 changes: 102 additions & 12 deletions test/sql/scanner/postgres_query.test
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -10,7 +10,7 @@ statement ok
ATTACH 'dbname=postgresscanner' AS s1 (TYPE POSTGRES)

query III
select * from postgres_query('s1', 'SELECT * FROM cars');
FROM postgres_query('s1', 'SELECT * FROM cars');
----
ferari testarosa red
aston martin db2 blue
Expand All @@ -19,12 +19,12 @@ ford T black

# filters
query III
select * from postgres_query('s1', 'SELECT * FROM cars WHERE color=''red''');
FROM postgres_query('s1', 'SELECT * FROM cars WHERE color=''red''');
----
ferari testarosa red

query III
select * from postgres_query('s1', 'SELECT * FROM cars') WHERE color='red';
FROM postgres_query('s1', 'SELECT * FROM cars') WHERE color='red';
----
ferari testarosa red

Expand Down Expand Up @@ -77,50 +77,50 @@ DATE[] TIME[] TIME WITH TIME ZONE[] TIMESTAMP[] TIMESTAMP WITH TIME ZONE[]

# semicolons
query III
select * from postgres_query('s1', 'SELECT * FROM cars;') WHERE color='red';
FROM postgres_query('s1', 'SELECT * FROM cars;') WHERE color='red';
----
ferari testarosa red

query III
select * from postgres_query('s1', 'SELECT * FROM cars; ; ') WHERE color='red';
FROM postgres_query('s1', 'SELECT * FROM cars; ; ') WHERE color='red';
----
ferari testarosa red

# incorrect usage
statement error
select * from postgres_query('s1', 'CREATE TABLE my_table(i INT)');
FROM postgres_query('s1', 'CREATE TABLE my_table(i INT)');
----
Invalid Error: Failed to execute query

# database not found
statement error
select * from postgres_query('xx', 'SELECT * FROM cars');
FROM postgres_query('xx', 'SELECT * FROM cars');
----
Binder Error: Failed to find attached database

mode skip

# empty statements
statement error
select * from postgres_query('s1', '') WHERE color='red';
FROM postgres_query('s1', '') WHERE color='red';
----
Invalid Error: Failed to execute query

statement error
select * from postgres_query('s1', ';;') WHERE color='red';
FROM postgres_query('s1', ';;') WHERE color='red';
----
Invalid Error: Failed to execute query

mode unskip

# NULL parameters
statement error
select * from postgres_query(NULL, 'SELECT 42');
FROM postgres_query(NULL, 'SELECT 42');
----
cannot be NULL

statement error
select * from postgres_query('s1', NULL);
FROM postgres_query('s1', NULL);
----
cannot be NULL

Expand All @@ -129,7 +129,7 @@ statement ok
ATTACH ':memory:' AS ddb

statement error
select * from postgres_query('ddb', 'SELECT * FROM cars');
FROM postgres_query('ddb', 'SELECT * FROM cars');
----
does not refer to a Postgres database

Expand Down Expand Up @@ -252,5 +252,95 @@ does not exist
statement ok
ROLLBACK

# wrapping rules

statement ok
CALL enable_logging('PostgresQueryLog')

# no wrap copy

query II
FROM postgres_query('s1', 'SELECT brand, model FROM cars', query_mode='COPY_BINARY');
----
ferari testarosa
aston martin db2
bentley mulsanne
ford T

query I
SELECT COUNT(*)
FROM duckdb_logs_parsed('PostgresQueryLog')
WHERE query = 'COPY (SELECT brand, model FROM cars) TO STDOUT (FORMAT "binary");'
----
1

# no wrap binary

query II
FROM postgres_query('s1', 'SELECT brand, model FROM cars', query_mode='PLAIN_QUERY_BINARY');
----
ferari testarosa
aston martin db2
bentley mulsanne
ford T

query I
SELECT COUNT(*)
FROM duckdb_logs_parsed('PostgresQueryLog')
WHERE query = 'SELECT brand, model FROM cars'
----
1

# no wrap text

query II
FROM postgres_query('s1', 'SELECT model, brand FROM cars', query_mode='PLAIN_QUERY_TEXT');
----
testarosa ferari
db2 aston martin
mulsanne bentley
T ford

query I
SELECT COUNT(*)
FROM duckdb_logs_parsed('PostgresQueryLog')
WHERE query = 'SELECT model, brand FROM cars'
----
1

# wrap color_t

query II
FROM postgres_query('s1', 'SELECT brand, color FROM cars', query_mode='PLAIN_QUERY_BINARY');
----
ferari red
aston martin blue
bentley gray
ford black

query I
SELECT COUNT(*)
FROM duckdb_logs_parsed('PostgresQueryLog')
WHERE query = 'SELECT "brand", "color"::VARCHAR FROM (SELECT brand, color FROM cars) AS __unnamed_subquery '
----
1

# wrap projection

query I
select count(*) from postgres_query('s1', 'SELECT * FROM cars WHERE color=''red''', query_mode='PLAIN_QUERY_BINARY');
----
1

query I
SELECT COUNT(*)
FROM duckdb_logs_parsed('PostgresQueryLog')
WHERE query = 'SELECT "brand" FROM (SELECT * FROM cars WHERE color=''red'') AS __unnamed_subquery '
----
1

statement ok
CALL disable_logging()

statement ok
DETACH s1
Loading