Add generate_series function

docs/en/sql-reference/table-functions/generate_series.md

@@ -0,0 +1,25 @@
+---
+slug: /en/sql-reference/table-functions/generate_series
+sidebar_position: 146
+sidebar_label: generate_series
+---
+
+# generate_series
+
+`generate_series(START, STOP)` - Returns a table with the single ‘generate_series’ column (UInt64) that contains integers from start to stop inclusively.
+
+`generate_series(START, STOP, STEP)` - Returns a table with the single ‘generate_series’ column (UInt64) that contains integers from start to stop inclusively with spacing between values given by STEP. 
+
+The following queries return tables with the same content but different column names:
+
+``` sql
+SELECT * FROM numbers(10, 5);
+SELECT * FROM generate_series(10, 14);
+```
+
+And the following queries return tables with the same content but different column names (but the second option is more efficient):
+
+``` sql
+SELECT * FROM numbers(10, 11) WHERE number % 3 == (10 % 3);
+SELECT * FROM generate_series(10, 20, 3) ;
+```

src/Common/iota.cpp

@@ -27,10 +27,39 @@ void iota(T * begin, size_t count, T first_value)
     return iotaImpl(begin, count, first_value);
 }
 
+MULTITARGET_FUNCTION_AVX2_SSE42(
+    MULTITARGET_FUNCTION_HEADER(template <iota_supported_types T> void NO_INLINE),
+    iotaWithStepImpl, MULTITARGET_FUNCTION_BODY((T * begin, size_t count, T first_value, T step) /// NOLINT
+    {
+        for (size_t i = 0; i < count; i++)
+            *(begin + i) = static_cast<T>(first_value + i * step);
+    })
+)
+
+template <iota_supported_types T>
+void iota_with_step(T * begin, size_t count, T first_value, T step)
+{
+#if USE_MULTITARGET_CODE
+    if (isArchSupported(TargetArch::AVX2))
+        return iotaWithStepImplAVX2(begin, count, first_value, step);
+
+    if (isArchSupported(TargetArch::SSE42))
+        return iotaWithStepImplSSE42(begin, count, first_value, step);
+#endif
+    return iotaWithStepImpl(begin, count, first_value, step);
+}
+
 template void iota(UInt8 * begin, size_t count, UInt8 first_value);
 template void iota(UInt32 * begin, size_t count, UInt32 first_value);
 template void iota(UInt64 * begin, size_t count, UInt64 first_value);
 #if defined(OS_DARWIN)
 template void iota(size_t * begin, size_t count, size_t first_value);
 #endif
+
+template void iota_with_step(UInt8 * begin, size_t count, UInt8 first_value, UInt8 step);
+template void iota_with_step(UInt32 * begin, size_t count, UInt32 first_value, UInt32 step);
+template void iota_with_step(UInt64 * begin, size_t count, UInt64 first_value, UInt64 step);
+#if defined(OS_DARWIN)
+template void iota_with_step(size_t * begin, size_t count, size_t first_value, size_t step);
+#endif
 }

src/Common/iota.h

@@ -31,4 +31,13 @@ extern template void iota(UInt64 * begin, size_t count, UInt64 first_value);
 #if defined(OS_DARWIN)
 extern template void iota(size_t * begin, size_t count, size_t first_value);
 #endif
+
+template <iota_supported_types T> void iota_with_step(T * begin, size_t count, T first_value, T step);
+
+extern template void iota_with_step(UInt8 * begin, size_t count, UInt8 first_value, UInt8 step);
+extern template void iota_with_step(UInt32 * begin, size_t count, UInt32 first_value, UInt32 step);
+extern template void iota_with_step(UInt64 * begin, size_t count, UInt64 first_value, UInt64 step);
+#if defined(OS_DARWIN)
+extern template void iota_with_step(size_t * begin, size_t count, size_t first_value, size_t step);
+#endif
 }