Polars SQL Differences¶

Math

factorial(x)

fact(x)

Factorial function. Values outside the supported integer factorial range return NULL.

polars-sql-test/new_sql_doc/functions-math.test

String

length(string)

char_length(string), character_length(string)

Character-count aliases.

polars-sql-test/new_sql_doc/functions-string.test

String

starts_with(string, prefix)

startwith(string, prefix), beginwith(string, prefix)

Prefix check.

polars-sql-test/new_sql_doc/functions-string.test

String

strpos(string, substring), position(substring IN string)

find(substring, string)

One-based substring position. find returns 0 when not found.

polars-sql-test/new_sql_doc/functions-string.test

Date and time

date_add(unit, value, timestamp)

dateadd(unit, value, timestamp)

Alias of date_add.

polars-sql-test/new_sql_doc/functions-datetime.test

Date and time

date_diff(unit, timestamp1, timestamp2)

date_diff(timestamp1, timestamp2, unit), datedif(timestamp1, timestamp2, unit)

Same difference direction: timestamp2 - timestamp1.

polars-sql-test/new_sql_doc/functions-datetime.test

functions.rst

lambda functions, bitwise functions, decimal-specific semantics, binary functions, JSON functions, noisy aggregate functions, array functions, map functions, URL extraction/encoding functions, IP address functions, geospatial functions, HyperLogLog, KHyperLogLog, QDigest, UUID, TDigest, color functions, session information functions, Teradata compatibility functions, internationalization functions, SetDigest, sketch, Pinot pushdown functions, plugin-loaded function listing, and table functions as inherited from the source documentation.

These function families do not have verified support for these scalar, aggregate, or window features. Some nearby Polars SQL-specific functions exist, but they are not the same documented function families and are not listed as equivalent syntax.

Polars SQL smoke tests for retained function families and unsupported boundary checks for representative removed function families.

polars-sql-test/new_sql_doc/functions-index.test

sql-functions/comparison.rst

greatest and least scalar functions, quantified comparison predicates using ALL, ANY, or SOME, and row-value tuple IN comparisons such as (a, b) IN ((1, 2)).

These forms do not have verified support. Polars SQL currently documents ordinary comparison operators, BETWEEN, null checks, IS DISTINCT FROM, LIKE, scalar IN/NOT IN, and single-column subquery IN/NOT IN for this page. Quantified comparison syntax has partial behavior, but complete SQL boolean semantics have not been verified.

Polars SQL tests for retained comparison behavior, unsupported boundary checks for removed forms, and manual verification of incomplete quantified comparison boolean semantics.

polars-sql-test/new_sql_doc/functions-comparison.test

sql-functions/conditional.rst

try(expression) conditional expression that catches selected runtime errors and returns NULL.

Polars SQL accepts TRY syntax in some contexts, but the behavior is not verified as supported.

Polars SQL test for retained conditional expressions and unsupported boundary check for TRY.

polars-sql-test/new_sql_doc/functions-conditional.test

sql-functions/conversion.rst

try_cast(value AS type) returning NULL on cast failure.

Polars SQL does not have verified try_cast semantics. Direct verification of TRY_CAST('abc' AS INTEGER) evaluated like a failing ordinary CAST instead of returning NULL.

Polars SQL test for retained CAST behavior and manual unsupported boundary check for try_cast failure behavior.

polars-sql-test/new_sql_doc/functions-conversion.test

sql-functions/conversion.rst

typeof(expr).

Polars SQL does not have a verified scalar function for returning expression type names.

Polars SQL unsupported function check.

polars-sql-test/new_sql_doc/functions-conversion.test

sql-functions/math.rst

cbrt, e, pi, pow alias, rand, random alias and bounded random, secure_rand/secure_random, sign, to_base, from_base, truncate, and width_bucket.

Polars SQL does not have verified scalar functions or compatible function-name mappings for these functions. Direct Polars SQL checks showed pi and rand do not behave as verified numeric functions.

Polars SQL unsupported function checks.

polars-sql-test/new_sql_doc/functions-math.test

sql-functions/math.rst

Probability CDF and inverse CDF functions, including beta_cdf, binomial_cdf, normal_cdf, inverse_beta_cdf, and inverse_normal_cdf.

Polars SQL does not have verified scalar functions for the probability distribution functions.

Polars SQL unsupported function checks.

polars-sql-test/new_sql_doc/functions-math.test

sql-functions/math.rst

Hyperbolic and floating-point helper functions cosh, tanh, infinity, nan, is_finite, is_infinite, and is_nan.

Polars SQL does not have verified scalar functions for these floating-point helper functions.

Polars SQL unsupported function checks.

polars-sql-test/new_sql_doc/functions-math.test

sql-functions/string.rst

bit_length and codepoint.

Polars SQL does not have verified compatible mappings for these names.

Polars SQL unsupported function checks.

polars-sql-test/new_sql_doc/functions-string.test

sql-functions/string.rst

hamming_distance, jarowinkler_similarity, levenshtein_distance, longest_common_prefix, and word_stem.

Polars SQL does not have verified scalar functions for these text similarity, prefix, and stemming functions.

Polars SQL unsupported function checks.

polars-sql-test/new_sql_doc/functions-string.test

sql-functions/string.rst

Unicode functions normalize, to_utf8, and from_utf8.

Polars SQL does not have verified scalar functions for these Unicode and binary conversion functions.

Polars SQL unsupported function checks.

polars-sql-test/new_sql_doc/functions-string.test

sql-functions/regexp.rst

regexp_extract_all, regexp_extract, regexp_like, and regexp_split.

Polars SQL does not have verified scalar mappings for these regexp functions. Array-returning forms are also outside the verified Polars SQL scalar documentation scope.

Polars SQL unsupported function checks.

polars-sql-test/new_sql_doc/functions-regexp.test

sql-functions/regexp.rst

Java Pattern syntax details and invalid-pattern error behavior.

Polars SQL regexp replacement does not follow source Java Pattern behavior. Direct verification showed invalid patterns return the original string rather than producing a compatible error.

Polars SQL incompatible behavior check.

polars-sql-test/new_sql_doc/functions-regexp.test

sql-functions/datetime.rst

date/time arithmetic operators over interval values and the AT TIME ZONE operator.

Polars SQL does not have verified compatible interval arithmetic or timestamp-with-time-zone operator support.

Polars SQL unsupported syntax checks.

polars-sql-test/new_sql_doc/functions-datetime.test

sql-functions/datetime.rst

last_day_of_month, from_iso8601_timestamp, from_iso8601_date, from_unixtime, to_iso8601, to_milliseconds, and to_unixtime.

Polars SQL does not have verified scalar functions for these date/time conversion helpers.

Polars SQL unsupported function checks.

polars-sql-test/new_sql_doc/functions-datetime.test

sql-functions/datetime.rst

extraction fields and aliases QUARTER via extract, WEEK, DAY_OF_WEEK, DOW, DAY_OF_YEAR, DOY, YEAR_OF_WEEK, YOW, TIMEZONE_HOUR, TIMEZONE_MINUTE, and convenience functions day_of_month, day_of_week, day_of_year, dow, doy, millisecond, timezone_hour, timezone_minute, week, week_of_year, year_of_week, and yow.

Polars SQL only has verified compatible extraction for YEAR, MONTH, DAY/DAY_OF_MONTH, HOUR, MINUTE, SECOND, and the convenience functions retained on the datetime page.

Polars SQL unsupported or incompatible extraction checks.

polars-sql-test/new_sql_doc/functions-datetime.test

sql-functions/aggregate.rst

General aggregates array_agg, bool_and, bool_or, every, checksum, geometric_mean, interval avg, reduce_agg, set_agg, and set_union.

Polars SQL only has verified support for the scalar-valued general aggregate functions retained on the aggregate page.

Polars SQL retained aggregate checks and representative unsupported function checks.

polars-sql-test/new_sql_doc/functions-aggregate.test

sql-functions/aggregate.rst

Top-N aggregate forms max(x, n) and min(x, n) that return arrays.

Direct Polars SQL verification showed these forms return scalar max(x) and min(x) values instead of compatible top-N arrays, so they are intentionally not documented as supported source behavior.

Polars SQL incompatible behavior check.

polars-sql-test/new_sql_doc/functions-aggregate.test

sql-functions/aggregate.rst

Map aggregate functions histogram, map_agg, map_union, map_union_sum, and multimap_agg.

Polars SQL does not have verified map-returning aggregate support for these functions.

Polars SQL unsupported function check.

polars-sql-test/new_sql_doc/functions-aggregate.test

sql-functions/aggregate.rst

Statistical aggregates entropy, kurtosis, and skewness.

Polars SQL does not have verified compatible aggregate functions for these statistical functions. Verified statistical support is limited to the covariance, correlation, regression, variance, and standard-deviation functions retained on the aggregate page.

Polars SQL retained statistical aggregate checks and unsupported function checks.

polars-sql-test/new_sql_doc/functions-aggregate.test

sql-functions/window.rst

GROUPS window frames.

Polars SQL does not support GROUPS frames. The retained window page documents only verified ROWS and RANGE frames.

Polars SQL unsupported frame check.

polars-sql-test/new_sql_doc/functions-window.test

language/types.rst

TINYINT type.

Polars SQL does not have verified TINYINT cast or support. SMALLINT is accepted but represented by the integer type and is documented separately.

Polars SQL unsupported cast check.

polars-sql-test/new_sql_doc/language-types.test

language/types.rst

Fixed-length CHAR(x) padding and comparison semantics.

Polars SQL accepts CHAR as a string type alias, but direct verification of CAST('abc' AS CHAR(7)) returned abc rather than a fixed-length padded value. The retained type page documents CHAR only as a string alias.

Polars SQL incompatible behavior check.

polars-sql-test/new_sql_doc/language-types.test

language/types.rst

TIME WITH TIME ZONE, TIMESTAMP WITH TIME ZONE, and interval types.

Polars SQL only has verified date/time support for DATE, TIME without time zone, and TIMESTAMP without time zone in this page. Time-zone and interval behavior is not verified as compatible.

Polars SQL unsupported time-zone/interval checks and datetime-page unsupported time-zone checks.

polars-sql-test/new_sql_doc/language-types.test

language/types.rst

Network, UUID, sketch, and geospatial types including IPADDRESS, IPPREFIX, UUID, HyperLogLog, P4HyperLogLog, KHyperLogLog, SetDigest, SfmSketch, QDigest, TDigest, KLL Sketch, and geospatial types.

Polars SQL does not have verified compatible support for these SQL-specific value and sketch types.

Polars SQL unsupported type checks for representative network and UUID literals.

polars-sql-test/new_sql_doc/language-types.test

language/reserved.rst

source reserved keyword table and SQL:2016/SQL-92 status columns.

Polars SQL uses its own parser grammar and reserved keyword set. The retained page lists Polars SQL parser reserved keywords instead of source parser/standard-status table.

Polars SQL checks for quoted reserved identifiers, unquoted reserved identifier rejection, and non-reserved keyword identifiers.

polars-sql-test/new_sql_doc/language-reserved.test

sql/alter-function.rst

ALTER FUNCTION statement for changing function null-call behavior.

Polars SQL does not have verified support for altering SQL function metadata.

Polars SQL unsupported statement check.

polars-sql-test/new_sql_doc/sql-alter-function.test

sql/alter-schema.rst

ALTER SCHEMA ... RENAME TO.

Schema rename is not supported.

Polars SQL unsupported statement check.

polars-sql-test/new_sql_doc/sql-alter-schema.test

sql/analyze.rst

connector-specific ANALYZE ... WITH (...) properties and Hive/Iceberg partition examples.

Polars SQL has verified support only for plain ANALYZE table_name in this page. Connector-specific analyze properties and catalog/schema examples are outside Polars SQL.

Polars SQL retained plain ANALYZE check.

polars-sql-test/new_sql_doc/sql-analyze.test

sql/commit.rst

COMMIT [ WORK ] transaction control statement.

Polars SQL does not have verified support for explicit transaction control SQL.

Polars SQL unsupported statement checks.

polars-sql-test/new_sql_doc/sql-commit.test

sql/create-role.rst

CREATE ROLE role-management statement.

Polars SQL does not have verified support for role management.

Polars SQL unsupported statement check.

polars-sql-test/new_sql_doc/sql-create-role.test

sql/create-table.rst

CREATE TABLE table/column comments, table and column connector properties, system.metadata.table_properties, system.metadata.column_properties, LIKE column copying, and table or column key constraints such as PRIMARY KEY and UNIQUE.

Polars SQL has verified support for ordinary column definitions, IF NOT EXISTS, and NOT NULL. Direct verification showed LIKE table creation fails in the SQL behavior, and PRIMARY KEY syntax does not enforce uniqueness. Connector property metadata and comment persistence are not verified as compatible source behavior.

Polars SQL retained CREATE TABLE checks plus incompatible PRIMARY KEY and unsupported LIKE checks.

polars-sql-test/new_sql_doc/sql-create-table.test

sql/create-vector-index.rst

CREATE VECTOR INDEX.

Polars SQL does not support vector-index DDL.

Polars SQL unsupported statement check.

polars-sql-test/new_sql_doc/sql-create-vector-index.test

sql/create-materialized-view.rst

CREATE MATERIALIZED VIEW.

Materialized-view creation is not supported.

Polars SQL unsupported statement check.

polars-sql-test/new_sql_doc/sql-create-materialized-view.test

sql/describe.rst

DESCRIBE table_name alias for SHOW COLUMNS.

DESCRIBE table inspection is not supported.

Polars SQL unsupported statement check against an existing table.

polars-sql-test/new_sql_doc/sql-describe.test

sql/drop-function.rst

DROP FUNCTION for user-defined SQL or temporary functions.

Polars SQL does not have verified support for dropping user-defined SQL functions.

Polars SQL unsupported statement check.

polars-sql-test/new_sql_doc/sql-drop-function.test

sql/drop-schema.rst

DROP SCHEMA IF EXISTS missing-schema suppression.

Polars SQL can drop existing schemas, but direct verification showed IF EXISTS does not suppress a missing-schema error.

Polars SQL retained DROP SCHEMA check and incompatible missing-schema IF EXISTS check.

polars-sql-test/new_sql_doc/sql-drop-schema.test

sql/execute.rst

EXECUTE prepared-statement execution.

Prepared-statement execution is not supported.

Polars SQL unsupported statement check.

polars-sql-test/new_sql_doc/sql-execute.test

sql/explain-analyze.rst

EXPLAIN ANALYZE runtime plan and operator statistics.

Polars SQL does not support EXPLAIN ANALYZE execution semantics or operator statistics output.

Polars SQL unsupported/incompatible statement check.

polars-sql-test/new_sql_doc/sql-explain-analyze.test

sql/merge.rst

MERGE conditional insert/update/delete statement.

MERGE is not supported.

Polars SQL unsupported statement check.

polars-sql-test/new_sql_doc/sql-merge.test

sql/refresh-materialized-view.rst

REFRESH MATERIALIZED VIEW.

Materialized-view refresh is not supported.

Polars SQL unsupported statement check.

polars-sql-test/new_sql_doc/sql-refresh-materialized-view.test

sql/revoke.rst and sql/revoke-roles.rst

Privilege revocation and role revocation.

Polars SQL does not have verified support for privilege or role-management SQL.

Polars SQL unsupported statement checks.

polars-sql-test/new_sql_doc/sql-revoke.test and polars-sql-test/new_sql_doc/sql-revoke-roles.test

sql/select.rst

WITH RECURSIVE.

Polars SQL reports recursive WITH queries as unsupported.

Polars SQL unsupported query check.

polars-sql-test/new_sql_doc/sql-select.test

sql/select.rst

UNNEST and WITH ORDINALITY.

Polars SQL does not have verified support for array or map unnesting.

Polars SQL unsupported query check.

polars-sql-test/new_sql_doc/sql-select.test

sql/select.rst

INTERSECT ALL and EXCEPT ALL multiset semantics.

Polars SQL verification covered distinct set semantics for INTERSECT and EXCEPT only. Multiset semantics are not documented as supported.

Polars SQL retained distinct set-operation checks.

polars-sql-test/new_sql_doc/sql-select.test

sql/set-session.rst

SET SESSION session-property assignment syntax.

Polars SQL does not have verified support for session-property control statements.

Polars SQL unsupported statement checks.

polars-sql-test/new_sql_doc/sql-set-session.test

sql/start-transaction.rst

START TRANSACTION transaction-control syntax.

Polars SQL does not have verified support for explicit transaction control SQL.

Polars SQL unsupported statement checks.

polars-sql-test/new_sql_doc/sql-start-transaction.test

sql/use.rst

USE catalog/schema session selection.

USE is not supported.

Polars SQL unsupported statement checks.

polars-sql-test/new_sql_doc/sql-use.test