Remove usage of usePostgreSQLDialect

docs/sql-migration-guide.md

@@ -256,7 +256,7 @@ license: |
 
   - Since Spark 3.0, the unary arithmetic operator plus(`+`) only accepts string, numeric and interval type values as inputs. Besides, `+` with a integral string representation will be coerced to double value, e.g. `+'1'` results `1.0`. In Spark version 2.4 and earlier, this operator is ignored. There is no type checking for it, thus, all type values with a `+` prefix are valid, e.g. `+ array(1, 2)` is valid and results `[1, 2]`. Besides, there is no type coercion for it at all, e.g. in Spark 2.4, the result of `+'1'` is string `1`.
 
-  - Since Spark 3.0, day-time interval strings are converted to intervals with respect to the `from` and `to` bounds. If an input string does not match to the pattern defined by specified bounds, the `ParseException` exception is thrown. For example, `interval '2 10:20' hour to minute` raises the exception because the expected format is `[+|-]h[h]:[m]m`. In Spark version 2.4, the `from` bound was not taken into account, and the `to` bound was used to truncate the resulted interval. For instance, the day-time interval string from the showed example is converted to `interval 10 hours 20 minutes`. To restore the behavior before Spark 3.0, you can set `spark.sql.legacy.fromDayTimeString.enabled` to `true` or set `spark.sql.dialect` to `PostgreSQL`.
+  - Since Spark 3.0, day-time interval strings are converted to intervals with respect to the `from` and `to` bounds. If an input string does not match to the pattern defined by specified bounds, the `ParseException` exception is thrown. For example, `interval '2 10:20' hour to minute` raises the exception because the expected format is `[+|-]h[h]:[m]m`. In Spark version 2.4, the `from` bound was not taken into account, and the `to` bound was used to truncate the resulted interval. For instance, the day-time interval string from the showed example is converted to `interval 10 hours 20 minutes`. To restore the behavior before Spark 3.0, you can set `spark.sql.legacy.fromDayTimeString.enabled` to `true`.
 
 ## Upgrading from Spark SQL 2.4 to 2.4.1
 

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/util/IntervalUtils.scala

@@ -168,8 +168,6 @@ object IntervalUtils {
   def fromDayTimeString(input: String, from: IntervalUnit, to: IntervalUnit): CalendarInterval = {
     if (SQLConf.get.getConf(SQLConf.LEGACY_FROM_DAYTIME_STRING)) {
       parseDayTimeLegacy(input, from, to)
-    } else if (SQLConf.get.usePostgreSQLDialect) {
-      parseDayTimeLegacy(input, from, to)
     } else {
       parseDayTime(input, from, to)
     }

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/util/IntervalUtilsSuite.scala

@@ -163,47 +163,43 @@ class IntervalUtilsSuite extends SparkFunSuite with SQLHelper {
   }
 
   test("from day-time string - legacy") {
-    Seq(
-      SQLConf.LEGACY_FROM_DAYTIME_STRING.key -> "true",
-      SQLConf.DIALECT.key -> "PostgreSQL").foreach { config =>
-      withSQLConf(config) {
-        assert(fromDayTimeString("5 12:40:30.999999999") ===
-          new CalendarInterval(
-            0,
-            5,
-            12 * MICROS_PER_HOUR +
-              40 * MICROS_PER_MINUTE +
-              30 * MICROS_PER_SECOND + 999999L))
-        assert(fromDayTimeString("10 0:12:0.888") ===
-          new CalendarInterval(
-            0,
-            10,
-            12 * MICROS_PER_MINUTE + 888 * MICROS_PER_MILLIS))
-        assert(fromDayTimeString("-3 0:0:0") === new CalendarInterval(0, -3, 0L))
-
-        try {
-          fromDayTimeString("5 30:12:20")
-          fail("Expected to throw an exception for the invalid input")
-        } catch {
-          case e: IllegalArgumentException =>
-            assert(e.getMessage.contains("hour 30 outside range"))
-        }
-
-        try {
-          fromDayTimeString("5 30-12")
-          fail("Expected to throw an exception for the invalid input")
-        } catch {
-          case e: IllegalArgumentException =>
-            assert(e.getMessage.contains("must match day-time format"))
-        }
-
-        try {
-          fromDayTimeString("5 1:12:20", HOUR, MICROSECOND)
-          fail("Expected to throw an exception for the invalid convention type")
-        } catch {
-          case e: IllegalArgumentException =>
-            assert(e.getMessage.contains("Cannot support (interval"))
-        }
+    withSQLConf(SQLConf.LEGACY_FROM_DAYTIME_STRING.key -> "true") {
+      assert(fromDayTimeString("5 12:40:30.999999999") ===
+        new CalendarInterval(
+          0,
+          5,
+          12 * MICROS_PER_HOUR +
+            40 * MICROS_PER_MINUTE +
+            30 * MICROS_PER_SECOND + 999999L))
+      assert(fromDayTimeString("10 0:12:0.888") ===
+        new CalendarInterval(
+          0,
+          10,
+          12 * MICROS_PER_MINUTE + 888 * MICROS_PER_MILLIS))
+      assert(fromDayTimeString("-3 0:0:0") === new CalendarInterval(0, -3, 0L))
+
+      try {
+        fromDayTimeString("5 30:12:20")
+        fail("Expected to throw an exception for the invalid input")
+      } catch {
+        case e: IllegalArgumentException =>
+          assert(e.getMessage.contains("hour 30 outside range"))
+      }
+
+      try {
+        fromDayTimeString("5 30-12")
+        fail("Expected to throw an exception for the invalid input")
+      } catch {
+        case e: IllegalArgumentException =>
+          assert(e.getMessage.contains("must match day-time format"))
+      }
+
+      try {
+        fromDayTimeString("5 1:12:20", HOUR, MICROSECOND)
+        fail("Expected to throw an exception for the invalid convention type")
+      } catch {
+        case e: IllegalArgumentException =>
+          assert(e.getMessage.contains("Cannot support (interval"))
       }
     }
   }