github.com/dolthub/dolt/go@v0.40.5-0.20240520175717-68db7794bea6/libraries/doltcore/schema/data_length.go (about)

     1  // Copyright 2023 Dolthub, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package schema
    16  
    17  import (
    18  	"github.com/dolthub/go-mysql-server/sql"
    19  	sqltypes "github.com/dolthub/go-mysql-server/sql/types"
    20  )
    21  
    22  func SchemaAvgLength(schema sql.Schema) uint64 {
    23  	var numBytesPerRow uint64 = 0
    24  	for _, col := range schema {
    25  		switch n := col.Type.(type) {
    26  		case sql.NumberType:
    27  			numBytesPerRow += 8
    28  		case sql.StringType:
    29  			numBytesPerRow += uint64(n.MaxByteLength())
    30  		case sqltypes.BitType:
    31  			numBytesPerRow += 8
    32  		case sql.DatetimeType:
    33  			numBytesPerRow += 8
    34  		case sql.DecimalType:
    35  			numBytesPerRow += uint64(n.MaximumScale())
    36  		case sql.EnumType:
    37  			numBytesPerRow += 2
    38  		case sqltypes.JsonType:
    39  			numBytesPerRow += 20
    40  		case sql.NullType:
    41  			numBytesPerRow += 1
    42  		case sqltypes.TimeType:
    43  			numBytesPerRow += 16
    44  		case sql.YearType:
    45  			numBytesPerRow += 8
    46  		}
    47  	}
    48  	return numBytesPerRow
    49  }