Results of 1 - 10 of about 21 for projection (0.002 sec.)
- Debugging 13615
- The purpose of the tests is to figure out when things break. Inevitably changes made to the system will cause one of the tests to fail, and when that happens the test needs to be debugged. First, it is always recommended to run in debug mod
...the filename of the breaking test to the test suite as a command line parameter (e.g., build/debug/test/unittest test/sql/projection/test_simple_projection.test ). For more options on running a subset of the tests see the Triggering which tests to run sec...e sqllogictests, this is the relative path to the test file. To run only a single test: build/debug/test/unittest test/sql/projection/test_simple_projection.test All tests in a given directory can be executed by providing the directory as a parameter with...square brackets. To run all tests in the “projection” directory: build/debug/test/unittest "[projection]" All tests, including the slow tests, can be run by running the tests... - https://man.mtool.work/duckdb/2.0/dev/sqllogictest/debugging.html
- sqllogictest Introduction 12482
- For testing plain SQL, we use an extended version of the SQL logic test suite, adopted from SQLite . Every test is a single self-contained file located in the test/sql directory. To run tests located outside of the default test directory, s
...sult, a statement ok indicator, or a statement error indicator. An example of a test file is shown below: # name: test/sql/projection/test_simple_projection.test # group [projection] # enable query verification statement ok PRAGMA enable_verification # cre...n the unittest group. For example, if we wanted to execute only the above test, we would run the command unittest test/sql/projection/test_simple_projection.test . If we wanted to run all tests in a specific directory, we would run the command unittest "[p... - https://man.mtool.work/duckdb/2.0/dev/sqllogictest/intro.html
- Table Functions 10604
- The table function API can be used to define a table function that can then be called from within DuckDB in the FROM clause of a query. API Reference Overview duckdb_table_function duckdb_create_table_function (); void duckdb_destroy_table_
..._function ( duckdb_table_function table_function , duckdb_table_function_t function ); void duckdb_table_function_supports_projection_pushdown ( duckdb_table_function table_function , bool pushdown ); duckdb_state duckdb_register_table_function ( duckdb_co...nction_t function ); Parameters table_function : The table function function : The function duckdb_table_function_supports_projection_pushdown Sets whether or not the given table function supports projection pushdown. If this is set to true, the system wil...set to false (the default), the system will expect all columns to be projected. Syntax void duckdb_table_function_supports_projection_pushdown ( duckdb_table_function table_function , bool pushdown ); Parameters table_function : The table function pushdown... - https://man.mtool.work/duckdb/2.0/clients/c/table_functions.html
- Directly Reading Files 8964
- DuckDB allows directly reading files via the read_text and read_blob functions. These functions accept a filename, a list of filenames, or a glob pattern. They output the content of each file as a VARCHAR or BLOB , respectively, along with
...not provide this data (e.g., HTTPFS may not always return a valid timestamp), the cell is set to NULL instead. Support for Projection Pushdown These table functions also use projection pushdown to avoid computing properties unnecessarily. For example, you... - https://man.mtool.work/duckdb/2.0/guides/file_formats/read_file.html
- Troubleshooting 8710
- Troubleshooting Running EXPLAIN Renders Newlines In Python, the output of the EXPLAIN statement contains hard line breaks ( \n ): In [1]: import duckdb ...: duckdb.sql("EXPLAIN SELECT 42 AS x") Out[1]: ┌───────────────┬─────────────────────
...────────────────────────────────────────────────────────────────────────────────────────────────────┤ │ physical_plan │ ╭─ Projection ───╮\n│ Projections: x │\n│ ~1 row │\n╰────────┬───────╯\n╭─ Dummy Scan ───╮\n │ │ │ ╰────────────────╯\n │ └─────────────...around this, print the output of the explain() function: In [2]: print(duckdb.sql("SELECT 42 AS x").explain()) Out[2]: ╭─ Projection ───╮ │ Projections: x │ │ ~1 row │ ╰────────┬───────╯ ╭─ Dummy Scan ───╮ ╰────────────────╯ In a Jupyter notebook, explain... - https://man.mtool.work/duckdb/2.0/clients/python/known_issues.html
- File Formats 8456
- Handling Parquet Files DuckDB has advanced support for Parquet files, which includes directly querying Parquet files . When deciding on whether to query these files directly or to first load them to the database, you need to consider severa
...format and contain basic statistics such as zonemaps . Thanks to these features, DuckDB can leverage optimizations such as projection and filter pushdown on Parquet files. Therefore, workloads that combine projection, filtering, and aggregation tend to per... - https://man.mtool.work/duckdb/2.0/guides/performance/file_formats.html
- Metrics 8203
- DuckDB provides a set of metrics that can be used to monitor the performance and health of the database. Metrics are named ⟨group⟩.⟨metric⟩ , e.g., query.total_time or operator.timing . The set of collected metrics is controlled with the tr
....top_n_window_elimination , optimizer.common_subplan , optimizer.join_elimination , optimizer.window_self_join , optimizer.projection_pullup , optimizer.outer_join_simplification , optimizer.row_number_rewriter , optimizer.partitioned_execution , optimizer..._rows": 0, "intermediate_size_bytes": 0, "timing": 5.458e-06, "type": "RESULT_COLLECTOR", "children": [ { "extra_info": { "Projections": "name", "Estimated Cardinality": "1" }, "intermediate_rows": 2, "intermediate_size_bytes": 40, "timing": 8.3e-08, "type...": "PROJECTION", "children": [ { "extra_info": { "Join Type": "INNER", "Conditions": "sid = sid", "Estimated Cardinality": "1" }, "interm... - https://man.mtool.work/duckdb/2.0/dev/metrics.html
- EXPLAIN: Inspect Query Plans 8084
- EXPLAIN SELECT * FROM tbl; The EXPLAIN statement displays the physical plan, i.e., the query plan that will get executed, and is enabled by prepending the query with EXPLAIN . The physical plan is a tree of operators that are executed in a
...'Chemistry', 2), (30, 'Literature', 3); EXPLAIN SELECT name FROM students JOIN exams USING (sid) WHERE name LIKE 'Ma%'; ╭─ Projection ─────────────╮ │ Projections: name │ │ ~1 row │ ╰─────────────┬────────────╯ ╭─ Hash Join ─┴────────────╮ │ Join Type: INN...──────╮ │ Table: memory.main.exams │ │ Table: memory.main.students │ │ Type: Sequential Scan │ │ Type: Sequential Scan │ │ Projections: sid │ │ Projections: sid, name │ │ ~3 rows │ │ Filters: name >= 'Ma' │ ╰──────────────────────────╯ │ ~1 row │ ╰────────... - https://man.mtool.work/duckdb/2.0/guides/meta/explain.html
- EXPLAIN ANALYZE: Profile Queries 8084
- Prepending a query with EXPLAIN ANALYZE both pretty-prints the query plan, and executes it, providing run-time performance numbers and the actual cardinality (number of rows produced) for every operator. EXPLAIN ANALYZE SELECT * FROM tbl; N
...s JOIN exams USING (sid) WHERE name LIKE 'Ma%'; ╭─ Summary ───────────╮ │ Total Time: 0.0015s │ ╰─────────────────────╯ ╭─ Projection ────────────────────────────────────────────╮ │ Projections: name │ │ 2 rows 0µs │ ╰────────────────────────────┒┎────────...──────╮ │ Table: memory.main.exams │ │ Table: memory.main.students │ │ Type: Sequential Scan │ │ Type: Sequential Scan │ │ Projections: sid │ │ Projections: sid, name │ │ Dynamic Filters: │ │ Filters: name >= 'Ma' │ │ optional: (sid IN (1, 3)) AND optional... - https://man.mtool.work/duckdb/2.0/guides/meta/explain_analyze.html
- Vector Similarity Search Extension 7949
- The vss extension is an experimental extension for DuckDB that adds indexing support to accelerate vector similarity search queries using DuckDB's new fixed-size ARRAY type. See the announcement blog post and the “What's New in the Vector S
...N SELECT * FROM my_vector_table ORDER BY array_distance(vec, [1, 2, 3]::FLOAT[3]) LIMIT 3; ┌───────────────────────────┐ │ PROJECTION │ │ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ │ │ #0 │ └─────────────┬─────────────┘ ┌─────────────┴─────────────┐ │ PROJECTION │ │ ─ ─ ─ ─ ─... - https://man.mtool.work/duckdb/2.0/core_extensions/vss.html
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