Added SHOW TABLES and DESCRIBE table support (apache#12293)

pinot-common/src/main/java/org/apache/pinot/common/function/scalar/ArrayFunctions.java

@@ -305,4 +305,48 @@ public static Object arrayValueConstructor(Object... arr) {
     }
     return arr;
   }
+
+  @ScalarFunction
+  public static int[] generateIntArray(int start, int end, int inc) {
+    int size = (end - start) / inc + 1;
+    int[] arr = new int[size];
+
+    for (int i = 0, value = start; i < size; i++, value += inc) {
+      arr[i] = value;
+    }
+    return arr;
+  }
+
+  @ScalarFunction
+  public static long[] generateLongArray(long start, long end, long inc) {
+    int size = (int) ((end - start) / inc + 1);
+    long[] arr = new long[size];
+
+    for (int i = 0; i < size; i++, start += inc) {
+      arr[i] = start;
+    }
+    return arr;
+  }
+
+  @ScalarFunction
+  public static float[] generateFloatArray(float start, float end, float inc) {
+    int size = (int) ((end - start) / inc + 1);
+    float[] arr = new float[size];
+
+    for (int i = 0; i < size; i++, start += inc) {
+      arr[i] = start;
+    }
+    return arr;
+  }
+
+  @ScalarFunction
+  public static double[] generateDoubleArray(double start, double end, double inc) {
+    int size = (int) ((end - start) / inc + 1);
+    double[] arr = new double[size];
+
+    for (int i = 0; i < size; i++, start += inc) {
+      arr[i] = start;
+    }
+    return arr;
+  }
 }

pinot-common/src/test/java/org/apache/pinot/common/function/FunctionDefinitionRegistryTest.java

@@ -42,8 +42,8 @@ public class FunctionDefinitionRegistryTest {
   private static final List<String> IGNORED_FUNCTION_NAMES = ImmutableList.of(
       // Geo functions are defined in pinot-core
       "geotoh3",
-      // ArrayToMV and ArrayValueConstructor are placeholder functions without implementation
-      "arraytomv", "arrayvalueconstructor",
+      // ArrayToMV, ArrayValueConstructor and GenerateArray are placeholder functions without implementation
+      "arraytomv", "arrayvalueconstructor", "generatearray",
       // Scalar function
       "scalar",
       // Functions without scalar function counterpart as of now