Results of 1 - 10 of about 12 for predicate (0.002 sec.)
- R-Tree Indexes 12841
- 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
...whose geometries intersect the query region have to be fetched from disk, and the often much more expensive exact spatial predicate check (and any other filters) only have to be executed for these rows. What Are the Limitations of R-Tree Indexes in DuckD...only be used to perform "index scans" when the table is filtered (using a WHERE clause) with one of the following spatial predicate functions (as they all imply intersection): ST_Equals , ST_Intersects , ST_Touches , ST_Crosses , ST_Within , ST_Contains..., ST_Overlaps , ST_Covers , ST_CoveredBy , ST_ContainsProperly . One of the arguments to the spatial predicate function must be a "constant" (i.e., an expression whose result is known at query planning time). This is because the quer... - https://man.mtool.work/duckdb/2.0/core_extensions/spatial/r-tree_indexes.html
- Boolean Type 11284
- Name Aliases Description BOOLEAN BOOL Logical Boolean ( true / false ) The BOOLEAN type represents a statement of truth (“true” or “false”). In SQL, the BOOLEAN field can also have a third state “unknown” which is represented by the SQL NUL
...n the WHERE and HAVING clauses of a SQL statement to filter out tuples from the result. In this case, tuples for which the predicate evaluates to true will pass the filter, and tuples for which the predicate evaluates to false or NULL will be filtered out... - https://man.mtool.work/duckdb/2.0/sql/data_types/boolean.html
- NULL Values 10612
- NULL values are special values that are used to represent missing data in SQL. Columns of any type can contain NULL values. Logically, a NULL value can be seen as “the value of this field is unknown”. A NULL value can be inserted to any fie
...values include: first , last , list and array_agg . To exclude NULL values from these results, use a FILTER clause with a predicate that excludes the relevant null rows, such as list(x) FILTER (WHERE x IS NOT NULL) . A different filter predicate does not... - https://man.mtool.work/duckdb/2.0/sql/data_types/nulls.html
- inet Extension 9286
- The inet extension defines the INET data type for storing IPv4 and IPv6 Internet addresses. It supports the CIDR notation for subnet masks (e.g., 198.51.100.0/22 , 2001:db8:3c4d::/48 ). Installing and Loading The inet extension will be tran
...cast 192.168.1.5/24 192.168.1.255/24 127.0.0.1 127.0.0.1 2001:db8:3c4d:15::1a2f:1a2b/96 2001:db8:3c4d:15::ffff:ffff/96 <<= Predicate Is subnet contained by or equal to subnet? CREATE TABLE tbl (cidr INET); INSERT INTO tbl VALUES ('192.168.1.0/24'), ('127....net_contained FROM tbl; cidr subnet_contained 192.168.1.0/24 true 127.0.0.1 false 2001:db8:3c4d:15::1a2f:1a2b/96 false >>= Predicate Does subnet contain or equal subnet? CREATE TABLE tbl (cidr INET); INSERT INTO tbl VALUES ('192.168.1.0/24'), ('127.0.0.1'... - https://man.mtool.work/duckdb/2.0/core_extensions/inet.html
- FROM and JOIN Clauses 8843
- The FROM clause specifies the source of the data on which the remainder of the query should operate. Logically, the FROM clause is where the query starts execution. The FROM clause can contain a single table, a combination of multiple table
...ult row has the columns from both relations. A join uses a rule to match pairs of rows from each relation. Often this is a predicate, but there are other implied rules that may be specified. Outer Joins Rows that do not have any matches can still be retur...This is equivalent to omitting the JOIN clause: SELECT a.*, b.* FROM a, b; Conditional Joins Most joins are specified by a predicate that connects attributes from one side to attributes from the other side. The conditions can be explicitly specified using...s: SELECT n.*, r.* FROM l_nations n JOIN l_regions r USING (regionkey); The expressions do not have to be equalities – any predicate can be used: Return the pairs of jobs where one ran longer but cost less: SELECT s1.t_id, s2.t_id FROM west s1, west s2 WH... - https://man.mtool.work/duckdb/2.0/sql/query_syntax/from.html
- Comparisons 8171
- Comparison Operators The table below shows the standard comparison operators. Whenever either of the input arguments is NULL , the output of the comparison is NULL . Operator Description Example Result < less than 2 < 3 true > greater than
...s below in the cases where both a , x and y are of the same type, as BETWEEN will cast all of its inputs to the same type. Predicate Description a BETWEEN x AND y equivalent to x <= a AND a <= y a NOT BETWEEN x AND y equivalent to x > a OR a > y expressio... - https://man.mtool.work/duckdb/2.0/sql/expressions/comparison_operators.html
- Parquet Tips 7941
- Below is a collection of tips to help when dealing with Parquet files. Tips for Reading Parquet Files Use union_by_name When Loading Files with Different Schemas The union_by_name option can be used to unify the schema of files that have di
...ment for smaller row group sizes is that DuckDB can read Parquet row groups in parallel even within the same file and uses predicate pushdown to only scan the row groups whose metadata ranges match the WHERE clause of the query. However, there is some ove... - https://man.mtool.work/duckdb/2.0/data/parquet/tips.html
- Variant Type 7941
- The VARIANT type stores typed, binary data where each row is self-contained with its own type information. This differs from the JSON type , which is physically stored as text. Because type metadata is embedded per-value, VARIANT provides b
...nto typed columns based on the structure of the first row group. This auto-shredding improves read performance by enabling predicate pushdown and efficient column access. To explicitly provide a schema for shredding, use the SHREDDING copy option: COPY ev... - https://man.mtool.work/duckdb/2.0/sql/data_types/variant.html
- Indexing 7729
- DuckDB has two types of indexes: zonemaps and ART indexes. Zonemaps DuckDB automatically creates zonemaps (also known as min-max indexes) for the columns of all general-purpose data types . Operations like predicate pushdown into scan opera
... - https://man.mtool.work/duckdb/2.0/guides/performance/indexing.html
- MySQL Extension 7269
- The mysql extension allows DuckDB to directly read and write data from/to a running MySQL instance. The data can be queried directly from the underlying MySQL database. Data can be loaded from MySQL tables into DuckDB tables, or vice versa.
...rint all queries sent to MySQL to stdout false mysql_enable_filter_pushdown Whether or not to use filter pushdown (without predicate analyzer) true mysql_enable_transactions Whether to run START TRANSACTION / COMMIT / ROLLBACK on MySQL connections true my... - https://man.mtool.work/duckdb/2.0/core_extensions/mysql.html
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