Results of 1 - 10 of about 14 for indexing (0.002 sec.)
- Indexing 12551
- DuckDB uses 1-based indexing except for JSON objects , which use 0-based indexing. Examples The index origin is 1 for strings, lists, etc. SELECT list[1] AS element FROM (SELECT ['first', 'second', 'third'] AS list); ┌─────────┐ │ element │
... - https://man.mtool.work/duckdb/2.0/sql/dialect/indexing.html
- SQL Quirks 11990
- Like all programming languages and libraries, DuckDB has its share of idiosyncrasies and inconsistencies. Some are vestiges of our feathered friend's evolution; others are inevitable because we strive to adhere to the SQL Standard and speci
...he list aggregate list_sum , but not by the DuckDB original list_dot_product which returns 0 on empty lists. 0 vs. 1-Based Indexing To comply with standard SQL, one-based indexing is used almost everywhere, e.g., array and string indexing and slicing, an...d window functions ( row_number , rank , dense_rank ). However, similarly to PostgreSQL, JSON features use a zero-based indexing . Types UINT8 vs. INT8 UINT8 and INT8 are aliases to integer types of different widths: UINT8 corresponds to UTINYINT beca... - https://man.mtool.work/duckdb/2.0/sql/dialect/sql_quirks.html
- JSON Overview 11413
- DuckDB supports SQL functions that are useful for reading values from existing JSON and creating new JSON data. JSON is supported with the json extension which is shipped with most DuckDB distributions and is auto-loaded on first use. If yo
...r transformations. It's best to pick either the JSONPath or the JSON Pointer syntax and use it in your entire application. Indexing Warning Following PostgreSQL's conventions , DuckDB uses 1-based indexing for its ARRAY and LIST data types but 0-based in... - https://man.mtool.work/duckdb/2.0/data/json/overview.html
- Interval Type 8542
- INTERVAL s represent periods of time that can be added to or subtracted from DATE , TIMESTAMP , TIMESTAMPTZ , or TIME values. Name Description INTERVAL Period of time An INTERVAL can be constructed by providing amounts together with units.
...atepart('microsecond', interval) // 1_000_000 millisecond datepart('microsecond', interval) // 1_000 All units use 0-based indexing, except for quarters, which use 1-based indexing. For example: SELECT datepart('decade', INTERVAL 12 YEARS), -- returns 1... - https://man.mtool.work/duckdb/2.0/sql/data_types/interval.html
- JSON Processing Functions 8349
- JSON Extraction Functions There are two extraction functions, which have their respective operators. The operators can only be used if the string is stored as the JSON logical type. These functions support the same two location notations as
...t(*) FROM (VALUES ('{}'::JSON)) t(j) WHERE 1 = 1 AND j->>'field' IS NOT NULL; Warning DuckDB's JSON data type uses 0-based indexing . Examples: CREATE TABLE example (j JSON); INSERT INTO example VALUES ('{ "family": "anatidae", "species": [ "duck", "goos...xample; duck SELECT j->'species'->>['/0', '/1'] FROM example; [duck, goose] Note that DuckDB's JSON data type uses 0-based indexing . If multiple values need to be extracted from the same JSON, it is more efficient to extract a list of paths: The followi...o the following: SELECT json_extract('{"duck": [1, 2, 3]}', '$.duck[0]'); 1 Note that DuckDB's JSON data type uses 0-based indexing . JSONPath is more expressive, and can also access from the back of lists: SELECT json_extract('{"duck": [1, 2, 3]}', '$.d... - https://man.mtool.work/duckdb/2.0/data/json/json_functions.html
- Out-of-Memory Issues 8349
- Configuration Options If you are experiencing out-of-memory issues with DuckDB, try tweaking the following configuration options: Reduce the number of threads using the SET threads = ... command. Setting the memory limit lower than the defa
...sumption. Additionally, they are currently not buffer-managed . Avoid using indexes if possible. If your workload requires indexing large tables, consider reducing the memory limit to accommodate this.... - https://man.mtool.work/duckdb/2.0/guides/performance/oom.html
- R-Tree Indexes 8157
- The spatial extension provides support for spatial indexing through the R-tree extension index type. Why Should I Use an R-Tree Index? When working with geospatial datasets, it is very common that you want to filter rows based on their spat
...not scale very well to large datasets as it always requires a full table scan to check every row in the table. However, by indexing a table with an R-tree, it is possible to accelerate these types of queries significantly. How Do R-Tree Indexes Work? An... - https://man.mtool.work/duckdb/2.0/core_extensions/spatial/r-tree_indexes.html
- Vector Similarity Search Extension 7964
- 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
...e each HNSW index only applies to a single column you can create multiple HNSW indexes on the same table each individually indexing a different column. Additionally, you can also create multiple HNSW indexes to the same column, each supporting a differen... - https://man.mtool.work/duckdb/2.0/core_extensions/vss.html
- ORDER BY Clause 7772
- ORDER BY is an output modifier. Logically it is applied near the very end of the query (just prior to LIMIT or OFFSET , if present). The ORDER BY clause sorts the rows on the sorting criteria in either ascending or descending order. In addi
...s may begin with either an arbitrary scalar expression (which could be a column name), a column position number (where the indexing starts from 1), or the keyword ALL . Each expression can optionally be followed by an order modifier ( ASC or DESC , defau... - https://man.mtool.work/duckdb/2.0/sql/query_syntax/orderby.html
- Prepared Statements 7772
- DuckDB supports prepared statements where parameters are substituted when the query is executed. This can improve readability and is useful for preventing SQL injections . Syntax There are three syntaxes for denoting parameters in prepared
...a single row <'Bob', 41> . Auto-Incremented Parameters: ? DuckDB supports using prepared statements with auto-incremented indexing, i.e., the position of the parameters in the query corresponds to their position in the execution statement. For example:... - https://man.mtool.work/duckdb/2.0/sql/query_syntax/prepared_statements.html
DuckDB 2.0 Documentation / man.mtool.work