[Enhance] Add "statistics" meta table and fix some mysql compatibility problem

be/src/exec/CMakeLists.txt

@@ -85,6 +85,7 @@ set(EXEC_FILES
     schema_scanner/schema_collations_scanner.cpp
     schema_scanner/schema_helper.cpp
     schema_scanner/schema_views_scanner.cpp
+    schema_scanner/schema_statistics_scanner.cpp
     schema_scanner/schema_table_privileges_scanner.cpp
     schema_scanner/schema_schema_privileges_scanner.cpp
     schema_scanner/schema_user_privileges_scanner.cpp

be/src/exec/schema_scanner.cpp

@@ -28,6 +28,7 @@
 #include "exec/schema_scanner/schema_user_privileges_scanner.h"
 #include "exec/schema_scanner/schema_variables_scanner.h"
 #include "exec/schema_scanner/schema_views_scanner.h"
+#include "exec/schema_scanner/schema_statistics_scanner.h"
 
 namespace doris {
 

be/src/exec/schema_scanner/schema_columns_scanner.cpp

@@ -131,7 +131,7 @@ std::string SchemaColumnsScanner::to_mysql_data_type_string(TColumnDesc& desc) {
 std::string SchemaColumnsScanner::type_to_string(TColumnDesc& desc) {
     switch (desc.columnType) {
     case TPrimitiveType::BOOLEAN:
-        return "tinyint(4)";
+        return "tinyint(1)";
     case TPrimitiveType::TINYINT:
         return "tinyint(4)";
     case TPrimitiveType::SMALLINT:

be/src/exec/schema_scanner/schema_statistics_scanner.cpp

@@ -0,0 +1,52 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+#include "exec/schema_scanner/schema_statistics_scanner.h"
+#include "runtime/primitive_type.h"
+#include "runtime/string_value.h"
+
+namespace doris {
+
+SchemaScanner::ColumnDesc SchemaStatisticsScanner::_s_cols_statistics[] = {
+    //   name,       type,          size,                     is_null
+    { "TABLE_CATALOG",      TYPE_VARCHAR, sizeof(StringValue),   true  },
+    { "TABLE_SCHEMA",       TYPE_VARCHAR, sizeof(StringValue),   false },
+    { "TABLE_NAME",         TYPE_VARCHAR, sizeof(StringValue),   false },
+    { "NON_UNIQUE",         TYPE_BIGINT, sizeof(int64_t),   false },
+    { "INDEX_SCHEMA",       TYPE_VARCHAR, sizeof(StringValue),   false },
+    { "INDEX_NAME",         TYPE_VARCHAR, sizeof(StringValue),   false },
+    { "SEQ_IN_INDEX",       TYPE_BIGINT, sizeof(int64_t),   false },
+    { "COLUMN_NAME",        TYPE_VARCHAR, sizeof(StringValue),   false },
+    { "COLLATION",          TYPE_VARCHAR, sizeof(StringValue),   true },
+    { "CARDINALITY",        TYPE_BIGINT, sizeof(int64_t),   true },
+    { "SUB_PART",           TYPE_BIGINT, sizeof(int64_t),   true },
+    { "PACKED",             TYPE_VARCHAR, sizeof(StringValue),   true },
+    { "NULLABLE",           TYPE_VARCHAR, sizeof(StringValue),   false },
+    { "INDEX_TYPE",         TYPE_VARCHAR, sizeof(StringValue),   false },
+    { "COMMENT",            TYPE_VARCHAR, sizeof(StringValue),   true },
+};
+
+SchemaStatisticsScanner::SchemaStatisticsScanner() :
+            SchemaScanner(_s_cols_statistics, sizeof(_s_cols_statistics) / sizeof(SchemaScanner::ColumnDesc)) {
+
+}
+
+SchemaStatisticsScanner::~SchemaStatisticsScanner() {
+
+}
+
+}

be/src/exec/schema_scanner/schema_statistics_scanner.h

@@ -0,0 +1,36 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+#ifndef DORIS_BE_SRC_QUERY_EXEC_SCHEMA_SCANNER_SCHEMA_STATISTICS_SCANNER_H
+#define DORIS_BE_SRC_QUERY_EXEC_SCHEMA_SCANNER_SCHEMA_STATISTICS_SCANNER_H
+
+#include "exec/schema_scanner.h"
+#include "gen_cpp/FrontendService_types.h"
+
+namespace doris {
+class SchemaStatisticsScanner : public SchemaScanner {
+public:
+    SchemaStatisticsScanner();
+    virtual ~SchemaStatisticsScanner();
+
+private:
+    static SchemaScanner::ColumnDesc _s_cols_statistics[];
+
+};
+}
+
+#endif // DORIS_BE_SRC_QUERY_EXEC_SCHEMA_SCANNER_SCHEMA_STATISTICS_SCANNER_H

fe/fe-core/src/main/java/org/apache/doris/catalog/PrimitiveType.java

@@ -546,6 +546,13 @@ public void setTimeType() {
         isTimeType = true;
     }
 
+    /**
+     * @return
+     */
+    public boolean isTimeType() {
+        return isTimeType;
+    }
+
     public static PrimitiveType fromThrift(TPrimitiveType tPrimitiveType) {
         switch (tPrimitiveType) {
             case INVALID_TYPE:
@@ -710,7 +717,7 @@ public MysqlColType toMysqlType() {
             }
             case DECIMAL:
             case DECIMALV2:
-                return MysqlColType.MYSQL_TYPE_DECIMAL;
+                return MysqlColType.MYSQL_TYPE_NEWDECIMAL;
             default:
                 return MysqlColType.MYSQL_TYPE_STRING;
         }

fe/fe-core/src/main/java/org/apache/doris/catalog/SchemaTable.java

@@ -322,7 +322,30 @@ public static Builder builder() {
                                         .column("CHARACTER_SET_CLIENT", ScalarType.createVarchar(32))
                                         .column("COLLATION_CONNECTION", ScalarType.createVarchar(32))
                                         .build()))
+                    .put("statistics",
+                            new SchemaTable(
+                                    SystemIdGenerator.getNextId(),
+                                    "statistics",
+                                    TableType.SCHEMA,
+                                    builder()
+                                            .column("TABLE_CATALOG", ScalarType.createVarchar(512))
+                                            .column("TABLE_SCHEMA", ScalarType.createVarchar(64))
+                                            .column("TABLE_NAME", ScalarType.createVarchar(64))
+                                            .column("NON_UNIQUE", ScalarType.createType(PrimitiveType.BIGINT))
+                                            .column("INDEX_SCHEMA", ScalarType.createVarchar(64))
+                                            .column("INDEX_NAME", ScalarType.createVarchar(64))
+                                            .column("SEQ_IN_INDEX", ScalarType.createType(PrimitiveType.BIGINT))
+                                            .column("COLUMN_NAME", ScalarType.createVarchar(64))
+                                            .column("COLLATION", ScalarType.createVarchar(1))
+                                            .column("CARDINALITY", ScalarType.createType(PrimitiveType.BIGINT))
+                                            .column("SUB_PART", ScalarType.createType(PrimitiveType.BIGINT))
+                                            .column("PACKED", ScalarType.createVarchar(10))
+                                            .column("NULLABLE", ScalarType.createVarchar(3))
+                                            .column("INDEX_TYPE", ScalarType.createVarchar(16))
+                                            .column("COMMENT", ScalarType.createVarchar(16))
+                                            .build()))
                     .build();
+    //  statistics is table provides information about table indexes in mysql: 5.7
     // views column is from show create table views in mysql: 5.5.6
 
     public static class Builder {

fe/fe-core/src/main/java/org/apache/doris/mysql/MysqlSerializer.java

@@ -214,7 +214,7 @@ public void writeField(String colName, PrimitiveType type) {
         // Character set: two byte integer
         writeInt2(33);
         // Column length: four byte integer
-        writeInt4(255);
+        writeInt4(getMysqlTypeLength(type));
         // Column type: one byte integer
         writeInt1(type.toMysqlType().getCode());
         // Flags: two byte integer
@@ -224,4 +224,49 @@ public void writeField(String colName, PrimitiveType type) {
         // filler: two byte integer
         writeInt2(0);
     }
+
+    /**
+     * Specify the display width of the returned data according to the MySQL type
+     * todo:The driver determines the number of bytes per character according to different character sets index
+     * @param type
+     * @return
+     */
+    private int getMysqlTypeLength(PrimitiveType type) {
+        switch (type) {
+            // MySQL use Tinyint(1) to represent boolean
+            case BOOLEAN:
+                return 1;
+            case TINYINT:
+                return 4;
+            case SMALLINT:
+                return 6;
+            case INT:
+                return 11;
+            case BIGINT:
+                return 20;
+            case FLOAT:
+                return 12;
+            case DOUBLE:
+                return 22;
+            case TIME:
+                return 10;
+            case DATE:
+                return 10;
+            case DATETIME: {
+                if (type.isTimeType()) {
+                    return 10;
+                }  else {
+                    return 19;
+                }
+            }
+            // todo:It needs to be obtained according to the field length set during the actual creation,
+            // todo:which is not supported for the time being.default is 255
+//            case DECIMAL:
+//            case DECIMALV2:
+//            case CHAR:
+//            case VARCHAR:
+            default:
+                return 255;
+        }
+    }
 }