twalthr commented on code in PR #27603:
URL: https://github.com/apache/flink/pull/27603#discussion_r2822405260
##########
flink-table/flink-table-common/src/main/java/org/apache/flink/table/types/logical/utils/LogicalTypeCasts.java:
##########
@@ -110,124 +114,216 @@ public final class LogicalTypeCasts {
private static final Map<LogicalTypeRoot, Set<LogicalTypeRoot>>
explicitCastingRules;
+ private static final Map<LogicalTypeRoot, List<InjectiveRule>>
injectiveRules;
+
+ // Types with deterministic, unique string representations (for injective
casts to STRING)
+ private static final LogicalTypeRoot[] STRING_INJECTIVE_SOURCES = {
+ TINYINT,
+ SMALLINT,
+ INTEGER,
+ BIGINT,
+ FLOAT,
+ DOUBLE,
+ BOOLEAN,
+ DATE,
+ TIME_WITHOUT_TIME_ZONE,
+ TIMESTAMP_WITHOUT_TIME_ZONE,
+ TIMESTAMP_WITH_LOCAL_TIME_ZONE
+ };
+
+ // ----- Injective cast conditions -----
+
+ /** Unconditionally injective (no additional type-parameter checks
needed). */
+ private static final BiPredicate<LogicalType, LogicalType> ALWAYS = (s, t)
-> true;
+
+ /** Injective when the target length can hold any value of the source
length. */
+ private static final BiPredicate<LogicalType, LogicalType>
WHEN_LENGTH_FITS =
+ (source, target) -> getLength(target) >= getLength(source);
+
+ /** Injective when the target length can hold the source type's max string
representation. */
+ private static final BiPredicate<LogicalType, LogicalType>
WHEN_MAX_CHAR_LENGTH_FITS =
+ (source, target) -> getLength(target) >=
maxStringRepresentationLength(source);
+
+ /** Injective when source and target share identical precision. */
+ private static final BiPredicate<LogicalType, LogicalType>
WHEN_PRECISION_MATCHES =
+ (source, target) -> getPrecision(source) == getPrecision(target);
+
+ /** Injective when source and target share identical precision and scale
(DECIMAL). */
+ private static final BiPredicate<LogicalType, LogicalType>
WHEN_PRECISION_AND_SCALE_MATCH =
+ (source, target) ->
+ getPrecision(source) == getPrecision(target)
+ && getScale(source) == getScale(target);
+
static {
implicitCastingRules = new HashMap<>();
explicitCastingRules = new HashMap<>();
+ injectiveRules = new HashMap<>();
- // identity casts
-
+ // Identity casts: all types can be implicitly cast to themselves.
+ // Injective identity for parameterized types is declared per-type
with conditions.
for (LogicalTypeRoot typeRoot : allTypes()) {
castTo(typeRoot).implicitFrom(typeRoot).build();
}
- // cast specification
+ //
-----------------------------------------------------------------------------------------
+ // Character string types
+ //
-----------------------------------------------------------------------------------------
castTo(CHAR)
.implicitFrom(CHAR)
.explicitFromFamily(PREDEFINED, CONSTRUCTED)
.explicitFrom(RAW, NULL, STRUCTURED_TYPE)
+ .injectiveFrom(WHEN_LENGTH_FITS, CHAR)
+ .injectiveFrom(WHEN_MAX_CHAR_LENGTH_FITS,
STRING_INJECTIVE_SOURCES)
.build();
castTo(VARCHAR)
.implicitFromFamily(CHARACTER_STRING)
.explicitFromFamily(PREDEFINED, CONSTRUCTED)
.explicitFrom(RAW, NULL, STRUCTURED_TYPE)
+ .injectiveFrom(WHEN_LENGTH_FITS, CHAR, VARCHAR)
+ .injectiveFrom(WHEN_MAX_CHAR_LENGTH_FITS,
STRING_INJECTIVE_SOURCES)
.build();
- castTo(BOOLEAN)
- .implicitFrom(BOOLEAN)
- .explicitFromFamily(CHARACTER_STRING, INTEGER_NUMERIC)
- .build();
+ //
-----------------------------------------------------------------------------------------
+ // Binary string types
+ //
-----------------------------------------------------------------------------------------
castTo(BINARY)
.implicitFrom(BINARY)
.explicitFromFamily(CHARACTER_STRING)
- .explicitFrom(VARBINARY)
- .explicitFrom(RAW)
+ .explicitFrom(VARBINARY, RAW)
+ .injectiveFrom(WHEN_LENGTH_FITS, BINARY)
.build();
castTo(VARBINARY)
.implicitFromFamily(BINARY_STRING)
.explicitFromFamily(CHARACTER_STRING)
- .explicitFrom(BINARY)
- .explicitFrom(RAW)
+ .explicitFrom(BINARY, RAW)
+ .injectiveFrom(WHEN_LENGTH_FITS, BINARY, VARBINARY)
.build();
- castTo(DECIMAL)
- .implicitFromFamily(NUMERIC)
- .explicitFromFamily(CHARACTER_STRING, INTERVAL)
- .explicitFrom(BOOLEAN, TIMESTAMP_WITHOUT_TIME_ZONE,
TIMESTAMP_WITH_LOCAL_TIME_ZONE)
- .build();
+ //
-----------------------------------------------------------------------------------------
+ // Exact numeric types
+ //
-----------------------------------------------------------------------------------------
castTo(TINYINT)
.implicitFrom(TINYINT)
.explicitFromFamily(NUMERIC, CHARACTER_STRING, INTERVAL)
.explicitFrom(BOOLEAN, TIMESTAMP_WITHOUT_TIME_ZONE,
TIMESTAMP_WITH_LOCAL_TIME_ZONE)
+ .injectiveFrom(ALWAYS, TINYINT)
.build();
castTo(SMALLINT)
.implicitFrom(TINYINT, SMALLINT)
.explicitFromFamily(NUMERIC, CHARACTER_STRING, INTERVAL)
.explicitFrom(BOOLEAN, TIMESTAMP_WITHOUT_TIME_ZONE,
TIMESTAMP_WITH_LOCAL_TIME_ZONE)
+ .injectiveFrom(ALWAYS, TINYINT, SMALLINT)
.build();
castTo(INTEGER)
.implicitFrom(TINYINT, SMALLINT, INTEGER)
.explicitFromFamily(NUMERIC, CHARACTER_STRING, INTERVAL)
.explicitFrom(BOOLEAN, TIMESTAMP_WITHOUT_TIME_ZONE,
TIMESTAMP_WITH_LOCAL_TIME_ZONE)
+ .injectiveFrom(ALWAYS, TINYINT, SMALLINT, INTEGER)
.build();
castTo(BIGINT)
.implicitFrom(TINYINT, SMALLINT, INTEGER, BIGINT)
.explicitFromFamily(NUMERIC, CHARACTER_STRING, INTERVAL)
.explicitFrom(BOOLEAN, TIMESTAMP_WITHOUT_TIME_ZONE,
TIMESTAMP_WITH_LOCAL_TIME_ZONE)
+ .injectiveFrom(ALWAYS, TINYINT, SMALLINT, INTEGER, BIGINT)
.build();
+ castTo(DECIMAL)
+ .implicitFromFamily(NUMERIC)
+ .explicitFromFamily(CHARACTER_STRING, INTERVAL)
+ .explicitFrom(BOOLEAN, TIMESTAMP_WITHOUT_TIME_ZONE,
TIMESTAMP_WITH_LOCAL_TIME_ZONE)
+ .injectiveFrom(WHEN_PRECISION_AND_SCALE_MATCH, DECIMAL)
+ .build();
+
+ //
-----------------------------------------------------------------------------------------
+ // Approximate numeric types
+ //
-----------------------------------------------------------------------------------------
+
castTo(FLOAT)
.implicitFrom(TINYINT, SMALLINT, INTEGER, BIGINT, FLOAT,
DECIMAL)
.explicitFromFamily(NUMERIC, CHARACTER_STRING)
.explicitFrom(BOOLEAN, TIMESTAMP_WITHOUT_TIME_ZONE,
TIMESTAMP_WITH_LOCAL_TIME_ZONE)
+ .injectiveFrom(ALWAYS, FLOAT)
.build();
castTo(DOUBLE)
.implicitFromFamily(NUMERIC)
.explicitFromFamily(CHARACTER_STRING)
.explicitFrom(BOOLEAN, TIMESTAMP_WITHOUT_TIME_ZONE,
TIMESTAMP_WITH_LOCAL_TIME_ZONE)
+ .injectiveFrom(ALWAYS, DOUBLE)
+ .build();
+
+ //
-----------------------------------------------------------------------------------------
+ // Boolean type
+ //
-----------------------------------------------------------------------------------------
+
+ castTo(BOOLEAN)
+ .implicitFrom(BOOLEAN)
+ .explicitFromFamily(CHARACTER_STRING, INTEGER_NUMERIC)
+ .injectiveFrom(ALWAYS, BOOLEAN)
.build();
+ //
-----------------------------------------------------------------------------------------
+ // Date and time types
+ //
-----------------------------------------------------------------------------------------
+
castTo(DATE)
.implicitFrom(DATE, TIMESTAMP_WITHOUT_TIME_ZONE)
.explicitFromFamily(TIMESTAMP, CHARACTER_STRING)
+ .injectiveFrom(ALWAYS, DATE)
.build();
castTo(TIME_WITHOUT_TIME_ZONE)
.implicitFrom(TIME_WITHOUT_TIME_ZONE,
TIMESTAMP_WITHOUT_TIME_ZONE)
.explicitFromFamily(TIME, TIMESTAMP, CHARACTER_STRING)
+ .injectiveFrom(WHEN_PRECISION_MATCHES, TIME_WITHOUT_TIME_ZONE)
.build();
castTo(TIMESTAMP_WITHOUT_TIME_ZONE)
.implicitFrom(TIMESTAMP_WITHOUT_TIME_ZONE,
TIMESTAMP_WITH_LOCAL_TIME_ZONE)
.explicitFromFamily(DATETIME, CHARACTER_STRING, NUMERIC)
+ .injectiveFrom(
+ WHEN_PRECISION_MATCHES,
+ TIMESTAMP_WITHOUT_TIME_ZONE,
+ TIMESTAMP_WITH_LOCAL_TIME_ZONE)
.build();
castTo(TIMESTAMP_WITH_TIME_ZONE)
.implicitFrom(TIMESTAMP_WITH_TIME_ZONE)
.explicitFromFamily(DATETIME, CHARACTER_STRING)
+ .injectiveFrom(WHEN_PRECISION_MATCHES,
TIMESTAMP_WITH_TIME_ZONE)
.build();
castTo(TIMESTAMP_WITH_LOCAL_TIME_ZONE)
.implicitFrom(TIMESTAMP_WITH_LOCAL_TIME_ZONE,
TIMESTAMP_WITHOUT_TIME_ZONE)
.explicitFromFamily(DATETIME, CHARACTER_STRING, NUMERIC)
+ .injectiveFrom(
+ WHEN_PRECISION_MATCHES,
+ TIMESTAMP_WITH_LOCAL_TIME_ZONE,
+ TIMESTAMP_WITHOUT_TIME_ZONE)
.build();
+ //
-----------------------------------------------------------------------------------------
+ // Interval types
+ //
-----------------------------------------------------------------------------------------
+
castTo(INTERVAL_YEAR_MONTH)
.implicitFrom(INTERVAL_YEAR_MONTH)
.explicitFromFamily(EXACT_NUMERIC, CHARACTER_STRING)
+ .injectiveFrom(ALWAYS, INTERVAL_YEAR_MONTH)
.build();
castTo(INTERVAL_DAY_TIME)
.implicitFrom(INTERVAL_DAY_TIME)
.explicitFromFamily(EXACT_NUMERIC, CHARACTER_STRING)
+ .injectiveFrom(ALWAYS, INTERVAL_DAY_TIME)
Review Comment:
there are also precisions here, better don't support in first version
##########
flink-table/flink-table-common/src/main/java/org/apache/flink/table/types/logical/utils/LogicalTypeCasts.java:
##########
@@ -110,124 +114,216 @@ public final class LogicalTypeCasts {
private static final Map<LogicalTypeRoot, Set<LogicalTypeRoot>>
explicitCastingRules;
+ private static final Map<LogicalTypeRoot, List<InjectiveRule>>
injectiveRules;
+
+ // Types with deterministic, unique string representations (for injective
casts to STRING)
+ private static final LogicalTypeRoot[] STRING_INJECTIVE_SOURCES = {
+ TINYINT,
+ SMALLINT,
+ INTEGER,
+ BIGINT,
+ FLOAT,
+ DOUBLE,
+ BOOLEAN,
+ DATE,
+ TIME_WITHOUT_TIME_ZONE,
+ TIMESTAMP_WITHOUT_TIME_ZONE,
+ TIMESTAMP_WITH_LOCAL_TIME_ZONE
+ };
+
+ // ----- Injective cast conditions -----
+
+ /** Unconditionally injective (no additional type-parameter checks
needed). */
+ private static final BiPredicate<LogicalType, LogicalType> ALWAYS = (s, t)
-> true;
+
+ /** Injective when the target length can hold any value of the source
length. */
+ private static final BiPredicate<LogicalType, LogicalType>
WHEN_LENGTH_FITS =
+ (source, target) -> getLength(target) >= getLength(source);
+
+ /** Injective when the target length can hold the source type's max string
representation. */
+ private static final BiPredicate<LogicalType, LogicalType>
WHEN_MAX_CHAR_LENGTH_FITS =
+ (source, target) -> getLength(target) >=
maxStringRepresentationLength(source);
+
+ /** Injective when source and target share identical precision. */
+ private static final BiPredicate<LogicalType, LogicalType>
WHEN_PRECISION_MATCHES =
+ (source, target) -> getPrecision(source) == getPrecision(target);
+
+ /** Injective when source and target share identical precision and scale
(DECIMAL). */
+ private static final BiPredicate<LogicalType, LogicalType>
WHEN_PRECISION_AND_SCALE_MATCH =
+ (source, target) ->
+ getPrecision(source) == getPrecision(target)
+ && getScale(source) == getScale(target);
+
static {
implicitCastingRules = new HashMap<>();
explicitCastingRules = new HashMap<>();
+ injectiveRules = new HashMap<>();
- // identity casts
-
+ // Identity casts: all types can be implicitly cast to themselves.
+ // Injective identity for parameterized types is declared per-type
with conditions.
for (LogicalTypeRoot typeRoot : allTypes()) {
castTo(typeRoot).implicitFrom(typeRoot).build();
}
- // cast specification
+ //
-----------------------------------------------------------------------------------------
+ // Character string types
+ //
-----------------------------------------------------------------------------------------
castTo(CHAR)
.implicitFrom(CHAR)
.explicitFromFamily(PREDEFINED, CONSTRUCTED)
.explicitFrom(RAW, NULL, STRUCTURED_TYPE)
+ .injectiveFrom(WHEN_LENGTH_FITS, CHAR)
+ .injectiveFrom(WHEN_MAX_CHAR_LENGTH_FITS,
STRING_INJECTIVE_SOURCES)
.build();
castTo(VARCHAR)
.implicitFromFamily(CHARACTER_STRING)
.explicitFromFamily(PREDEFINED, CONSTRUCTED)
.explicitFrom(RAW, NULL, STRUCTURED_TYPE)
+ .injectiveFrom(WHEN_LENGTH_FITS, CHAR, VARCHAR)
+ .injectiveFrom(WHEN_MAX_CHAR_LENGTH_FITS,
STRING_INJECTIVE_SOURCES)
.build();
- castTo(BOOLEAN)
- .implicitFrom(BOOLEAN)
- .explicitFromFamily(CHARACTER_STRING, INTEGER_NUMERIC)
- .build();
+ //
-----------------------------------------------------------------------------------------
+ // Binary string types
+ //
-----------------------------------------------------------------------------------------
castTo(BINARY)
.implicitFrom(BINARY)
.explicitFromFamily(CHARACTER_STRING)
- .explicitFrom(VARBINARY)
- .explicitFrom(RAW)
+ .explicitFrom(VARBINARY, RAW)
+ .injectiveFrom(WHEN_LENGTH_FITS, BINARY)
.build();
castTo(VARBINARY)
.implicitFromFamily(BINARY_STRING)
.explicitFromFamily(CHARACTER_STRING)
- .explicitFrom(BINARY)
- .explicitFrom(RAW)
+ .explicitFrom(BINARY, RAW)
+ .injectiveFrom(WHEN_LENGTH_FITS, BINARY, VARBINARY)
.build();
- castTo(DECIMAL)
- .implicitFromFamily(NUMERIC)
- .explicitFromFamily(CHARACTER_STRING, INTERVAL)
- .explicitFrom(BOOLEAN, TIMESTAMP_WITHOUT_TIME_ZONE,
TIMESTAMP_WITH_LOCAL_TIME_ZONE)
- .build();
+ //
-----------------------------------------------------------------------------------------
+ // Exact numeric types
+ //
-----------------------------------------------------------------------------------------
castTo(TINYINT)
.implicitFrom(TINYINT)
.explicitFromFamily(NUMERIC, CHARACTER_STRING, INTERVAL)
.explicitFrom(BOOLEAN, TIMESTAMP_WITHOUT_TIME_ZONE,
TIMESTAMP_WITH_LOCAL_TIME_ZONE)
+ .injectiveFrom(ALWAYS, TINYINT)
.build();
castTo(SMALLINT)
.implicitFrom(TINYINT, SMALLINT)
.explicitFromFamily(NUMERIC, CHARACTER_STRING, INTERVAL)
.explicitFrom(BOOLEAN, TIMESTAMP_WITHOUT_TIME_ZONE,
TIMESTAMP_WITH_LOCAL_TIME_ZONE)
+ .injectiveFrom(ALWAYS, TINYINT, SMALLINT)
.build();
castTo(INTEGER)
.implicitFrom(TINYINT, SMALLINT, INTEGER)
.explicitFromFamily(NUMERIC, CHARACTER_STRING, INTERVAL)
.explicitFrom(BOOLEAN, TIMESTAMP_WITHOUT_TIME_ZONE,
TIMESTAMP_WITH_LOCAL_TIME_ZONE)
+ .injectiveFrom(ALWAYS, TINYINT, SMALLINT, INTEGER)
.build();
castTo(BIGINT)
.implicitFrom(TINYINT, SMALLINT, INTEGER, BIGINT)
.explicitFromFamily(NUMERIC, CHARACTER_STRING, INTERVAL)
.explicitFrom(BOOLEAN, TIMESTAMP_WITHOUT_TIME_ZONE,
TIMESTAMP_WITH_LOCAL_TIME_ZONE)
+ .injectiveFrom(ALWAYS, TINYINT, SMALLINT, INTEGER, BIGINT)
.build();
+ castTo(DECIMAL)
+ .implicitFromFamily(NUMERIC)
+ .explicitFromFamily(CHARACTER_STRING, INTERVAL)
+ .explicitFrom(BOOLEAN, TIMESTAMP_WITHOUT_TIME_ZONE,
TIMESTAMP_WITH_LOCAL_TIME_ZONE)
+ .injectiveFrom(WHEN_PRECISION_AND_SCALE_MATCH, DECIMAL)
+ .build();
+
+ //
-----------------------------------------------------------------------------------------
+ // Approximate numeric types
+ //
-----------------------------------------------------------------------------------------
+
castTo(FLOAT)
.implicitFrom(TINYINT, SMALLINT, INTEGER, BIGINT, FLOAT,
DECIMAL)
.explicitFromFamily(NUMERIC, CHARACTER_STRING)
.explicitFrom(BOOLEAN, TIMESTAMP_WITHOUT_TIME_ZONE,
TIMESTAMP_WITH_LOCAL_TIME_ZONE)
+ .injectiveFrom(ALWAYS, FLOAT)
.build();
castTo(DOUBLE)
.implicitFromFamily(NUMERIC)
.explicitFromFamily(CHARACTER_STRING)
.explicitFrom(BOOLEAN, TIMESTAMP_WITHOUT_TIME_ZONE,
TIMESTAMP_WITH_LOCAL_TIME_ZONE)
+ .injectiveFrom(ALWAYS, DOUBLE)
+ .build();
+
+ //
-----------------------------------------------------------------------------------------
+ // Boolean type
+ //
-----------------------------------------------------------------------------------------
+
+ castTo(BOOLEAN)
+ .implicitFrom(BOOLEAN)
+ .explicitFromFamily(CHARACTER_STRING, INTEGER_NUMERIC)
+ .injectiveFrom(ALWAYS, BOOLEAN)
.build();
+ //
-----------------------------------------------------------------------------------------
+ // Date and time types
+ //
-----------------------------------------------------------------------------------------
+
castTo(DATE)
.implicitFrom(DATE, TIMESTAMP_WITHOUT_TIME_ZONE)
.explicitFromFamily(TIMESTAMP, CHARACTER_STRING)
+ .injectiveFrom(ALWAYS, DATE)
.build();
castTo(TIME_WITHOUT_TIME_ZONE)
.implicitFrom(TIME_WITHOUT_TIME_ZONE,
TIMESTAMP_WITHOUT_TIME_ZONE)
.explicitFromFamily(TIME, TIMESTAMP, CHARACTER_STRING)
+ .injectiveFrom(WHEN_PRECISION_MATCHES, TIME_WITHOUT_TIME_ZONE)
.build();
castTo(TIMESTAMP_WITHOUT_TIME_ZONE)
.implicitFrom(TIMESTAMP_WITHOUT_TIME_ZONE,
TIMESTAMP_WITH_LOCAL_TIME_ZONE)
.explicitFromFamily(DATETIME, CHARACTER_STRING, NUMERIC)
+ .injectiveFrom(
+ WHEN_PRECISION_MATCHES,
+ TIMESTAMP_WITHOUT_TIME_ZONE,
+ TIMESTAMP_WITH_LOCAL_TIME_ZONE)
.build();
castTo(TIMESTAMP_WITH_TIME_ZONE)
.implicitFrom(TIMESTAMP_WITH_TIME_ZONE)
.explicitFromFamily(DATETIME, CHARACTER_STRING)
+ .injectiveFrom(WHEN_PRECISION_MATCHES,
TIMESTAMP_WITH_TIME_ZONE)
.build();
castTo(TIMESTAMP_WITH_LOCAL_TIME_ZONE)
.implicitFrom(TIMESTAMP_WITH_LOCAL_TIME_ZONE,
TIMESTAMP_WITHOUT_TIME_ZONE)
.explicitFromFamily(DATETIME, CHARACTER_STRING, NUMERIC)
+ .injectiveFrom(
+ WHEN_PRECISION_MATCHES,
+ TIMESTAMP_WITH_LOCAL_TIME_ZONE,
+ TIMESTAMP_WITHOUT_TIME_ZONE)
.build();
+ //
-----------------------------------------------------------------------------------------
+ // Interval types
+ //
-----------------------------------------------------------------------------------------
+
castTo(INTERVAL_YEAR_MONTH)
.implicitFrom(INTERVAL_YEAR_MONTH)
.explicitFromFamily(EXACT_NUMERIC, CHARACTER_STRING)
+ .injectiveFrom(ALWAYS, INTERVAL_YEAR_MONTH)
Review Comment:
there are also precisions here, better don't support in first version
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