Sync Master

sql/core/src/main/scala/org/apache/spark/sql/jdbc/JdbcDialects.scala

@@ -96,17 +96,6 @@ abstract class JdbcDialect {
   def quoteIdentifier(colName: String): String = {
     s""""$colName""""
   }
-
-  /**
-   * Get the SQL query that should be used to find if the given table exists. Dialects can
-   * override this method to return a query that works best in a particular database.
-   * @param table  The name of the table.
-   * @return The SQL query to use for checking the table.
-   */
-  def getTableExistsQuery(table: String): String = {
-    s"SELECT * FROM $table WHERE 1=0"
-  }
-
 }
 
 /**
@@ -222,11 +211,6 @@ case object PostgresDialect extends JdbcDialect {
     case BooleanType => Some(JdbcType("BOOLEAN", java.sql.Types.BOOLEAN))
     case _ => None
   }
-
-  override def getTableExistsQuery(table: String): String = {
-    s"SELECT 1 FROM $table LIMIT 1"
-  }
-
 }
 
 /**
@@ -251,10 +235,6 @@ case object MySQLDialect extends JdbcDialect {
   override def quoteIdentifier(colName: String): String = {
     s"`$colName`"
   }
-
-  override def getTableExistsQuery(table: String): String = {
-    s"SELECT 1 FROM $table LIMIT 1"
-  }
 }
 
 /**