diff --git a/core/src/main/java/org/apache/calcite/adapter/enumerable/RexImpTable.java b/core/src/main/java/org/apache/calcite/adapter/enumerable/RexImpTable.java
index 3f63268eeaf..b43624bc753 100644
--- a/core/src/main/java/org/apache/calcite/adapter/enumerable/RexImpTable.java
+++ b/core/src/main/java/org/apache/calcite/adapter/enumerable/RexImpTable.java
@@ -222,6 +222,7 @@
import static org.apache.calcite.sql.fun.SqlLibraryOperators.LEFT;
import static org.apache.calcite.sql.fun.SqlLibraryOperators.LEVENSHTEIN;
import static org.apache.calcite.sql.fun.SqlLibraryOperators.LOG;
+import static org.apache.calcite.sql.fun.SqlLibraryOperators.LOG1P;
import static org.apache.calcite.sql.fun.SqlLibraryOperators.LOG2;
import static org.apache.calcite.sql.fun.SqlLibraryOperators.LOGICAL_AND;
import static org.apache.calcite.sql.fun.SqlLibraryOperators.LOGICAL_OR;
@@ -747,6 +748,7 @@ Builder populate() {
defineMethod(TANH, BuiltInMethod.TANH.method, NullPolicy.STRICT);
defineMethod(TRUNC_BIG_QUERY, BuiltInMethod.STRUNCATE.method, NullPolicy.STRICT);
defineMethod(TRUNCATE, BuiltInMethod.STRUNCATE.method, NullPolicy.STRICT);
+ defineMethod(LOG1P, BuiltInMethod.LOG1P.method, NullPolicy.STRICT);
map.put(SAFE_ADD,
new SafeArithmeticImplementor(BuiltInMethod.SAFE_ADD.method));
diff --git a/core/src/main/java/org/apache/calcite/runtime/SqlFunctions.java b/core/src/main/java/org/apache/calcite/runtime/SqlFunctions.java
index ba60ed6e5b1..c6cdc64e650 100644
--- a/core/src/main/java/org/apache/calcite/runtime/SqlFunctions.java
+++ b/core/src/main/java/org/apache/calcite/runtime/SqlFunctions.java
@@ -3061,6 +3061,16 @@ public static double power(BigDecimal b0, BigDecimal b1) {
return Math.log(number.doubleValue()) / Math.log(base.doubleValue());
}
+ /** SQL LOG1P
operator applied to double values. */
+ public static @Nullable Double log1p(double b0) {
+ return b0 <= -1 ? null : Math.log1p(b0);
+ }
+
+ /** SQL LOG1P
operator applied to BigDecimal values. */
+ public static @Nullable Double log1p(BigDecimal b0) {
+ return b0.doubleValue() <= -1 ? null : Math.log1p(b0.doubleValue());
+ }
+
// MOD
/** SQL MOD
operator applied to byte values. */
diff --git a/core/src/main/java/org/apache/calcite/sql/fun/SqlLibraryOperators.java b/core/src/main/java/org/apache/calcite/sql/fun/SqlLibraryOperators.java
index e882697af69..bbdaab50963 100644
--- a/core/src/main/java/org/apache/calcite/sql/fun/SqlLibraryOperators.java
+++ b/core/src/main/java/org/apache/calcite/sql/fun/SqlLibraryOperators.java
@@ -2525,6 +2525,14 @@ private static RelDataType deriveTypeMapFromEntries(SqlOperatorBinding opBinding
OperandTypes.NUMERIC,
SqlFunctionCategory.NUMERIC);
+ /** The "LOG1p(numeric)" function. Returns log(1 + numeric). */
+ @LibraryOperator(libraries = {SPARK})
+ public static final SqlFunction LOG1P =
+ SqlBasicFunction.create("LOG1P",
+ ReturnTypes.DOUBLE_FORCE_NULLABLE,
+ OperandTypes.NUMERIC,
+ SqlFunctionCategory.NUMERIC);
+
@LibraryOperator(libraries = {BIG_QUERY, SPARK})
public static final SqlFunction POW =
SqlBasicFunction.create("POW",
diff --git a/core/src/main/java/org/apache/calcite/util/BuiltInMethod.java b/core/src/main/java/org/apache/calcite/util/BuiltInMethod.java
index 64aafb11e7c..c5b53555534 100644
--- a/core/src/main/java/org/apache/calcite/util/BuiltInMethod.java
+++ b/core/src/main/java/org/apache/calcite/util/BuiltInMethod.java
@@ -558,6 +558,7 @@ public enum BuiltInMethod {
SAFE_MULTIPLY(SqlFunctions.class, "safeMultiply", double.class, double.class),
SAFE_SUBTRACT(SqlFunctions.class, "safeSubtract", double.class, double.class),
LOG(SqlFunctions.class, "log", long.class, long.class, boolean.class),
+ LOG1P(SqlFunctions.class, "log1p", long.class),
SEC(SqlFunctions.class, "sec", double.class),
SECH(SqlFunctions.class, "sech", double.class),
SIGN(SqlFunctions.class, "sign", long.class),
diff --git a/site/_docs/reference.md b/site/_docs/reference.md
index a57486c7a26..b7873ca8999 100644
--- a/site/_docs/reference.md
+++ b/site/_docs/reference.md
@@ -2853,6 +2853,7 @@ In the following:
| m s | LOG([, base ], numeric1) | Returns the logarithm of *numeric1* to base *base*, or base e if *base* is not present, or null if *numeric1* is 0 or negative
| p | LOG([, base ], numeric1 ) | Returns the logarithm of *numeric1* to base *base*, or base 10 if *numeric1* is not present, or error if *numeric1* is 0 or negative
| m s | LOG2(numeric) | Returns the base 2 logarithm of *numeric*
+| s | LOG1P(numeric) | Returns the natural logarithm of 1 plus *numeric*
| b o p r s | LPAD(string, length [, pattern ]) | Returns a string or bytes value that consists of *string* prepended to *length* with *pattern*
| b | TO_BASE32(string) | Converts the *string* to base-32 encoded form and returns an encoded string
| b | FROM_BASE32(string) | Returns the decoded result of a base-32 *string* as a string
diff --git a/testkit/src/main/java/org/apache/calcite/test/SqlOperatorTest.java b/testkit/src/main/java/org/apache/calcite/test/SqlOperatorTest.java
index 3a04c8f6bb1..825364586cd 100644
--- a/testkit/src/main/java/org/apache/calcite/test/SqlOperatorTest.java
+++ b/testkit/src/main/java/org/apache/calcite/test/SqlOperatorTest.java
@@ -7372,6 +7372,31 @@ void checkRegexpExtract(SqlOperatorFixture f0, FunctionAlias functionAlias) {
"Cannot take logarithm of zero or negative number", true);
}
+ /** Test case for
+ * [CALCITE-6549]
+ * Add LOG1P function (enabled in Spark library). */
+ @Test void testLog1PFunc() {
+ final SqlOperatorFixture f0 = fixture()
+ .setFor(SqlLibraryOperators.LOG1P, VmName.EXPAND);
+ f0.checkFails("^log1p(4)^",
+ "No match found for function signature LOG1P\\(\\)", false);
+ final SqlOperatorFixture f = f0.withLibrary(SqlLibrary.SPARK);
+ f.checkScalarApprox("log1p(0)", "DOUBLE",
+ isWithin(0.0, 0.000001));
+ f.checkScalarApprox("log1p(1)", "DOUBLE",
+ isWithin(0.6931471805599453, 0.000001));
+ f.checkScalarApprox("log1p(1e+22)", "DOUBLE",
+ isWithin(50.65687204586901, 0.000001));
+ f.checkScalarApprox("log1p(1.2)", "DOUBLE",
+ isWithin(0.7884573603642702, 0.000001));
+ f.checkScalarApprox("log1p(2.0/3)", "DOUBLE",
+ isWithin(0.5108256237659907, 0.000001));
+ f.checkNull("log1p(cast(null as real))");
+ f.checkNull("log1p(-1)");
+ f.checkNull("log1p(null)");
+ f.checkFails("^log1p()^", INVALID_ARGUMENTS_NUMBER, false);
+ }
+
@Test void testRandFunc() {
final SqlOperatorFixture f = fixture();
f.setFor(SqlStdOperatorTable.RAND, VmName.EXPAND);