1// Copyright 2018 Google LLC 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 15package spanner 16 17import ( 18 "context" 19 20 "cloud.google.com/go/internal/trace" 21 "github.com/googleapis/gax-go/v2" 22 sppb "google.golang.org/genproto/googleapis/spanner/v1" 23 "google.golang.org/grpc/codes" 24) 25 26// PartitionedUpdate executes a DML statement in parallel across the database, 27// using separate, internal transactions that commit independently. The DML 28// statement must be fully partitionable: it must be expressible as the union 29// of many statements each of which accesses only a single row of the table. The 30// statement should also be idempotent, because it may be applied more than once. 31// 32// PartitionedUpdate returns an estimated count of the number of rows affected. 33// The actual number of affected rows may be greater than the estimate. 34func (c *Client) PartitionedUpdate(ctx context.Context, statement Statement) (count int64, err error) { 35 return c.partitionedUpdate(ctx, statement, c.qo) 36} 37 38// PartitionedUpdateWithOptions executes a DML statement in parallel across the database, 39// using separate, internal transactions that commit independently. The sql 40// query execution will be optimized based on the given query options. 41func (c *Client) PartitionedUpdateWithOptions(ctx context.Context, statement Statement, opts QueryOptions) (count int64, err error) { 42 return c.partitionedUpdate(ctx, statement, c.qo.merge(opts)) 43} 44 45func (c *Client) partitionedUpdate(ctx context.Context, statement Statement, options QueryOptions) (count int64, err error) { 46 ctx = trace.StartSpan(ctx, "cloud.google.com/go/spanner.PartitionedUpdate") 47 defer func() { trace.EndSpan(ctx, err) }() 48 if err := checkNestedTxn(ctx); err != nil { 49 return 0, err 50 } 51 52 sh, err := c.idleSessions.take(ctx) 53 if err != nil { 54 return 0, toSpannerError(err) 55 } 56 if sh != nil { 57 defer sh.recycle() 58 } 59 60 // Create the parameters and the SQL request, but without a transaction. 61 // The transaction reference will be added by the executePdml method. 62 params, paramTypes, err := statement.convertParams() 63 if err != nil { 64 return 0, toSpannerError(err) 65 } 66 req := &sppb.ExecuteSqlRequest{ 67 Session: sh.getID(), 68 Sql: statement.SQL, 69 Params: params, 70 ParamTypes: paramTypes, 71 QueryOptions: options.Options, 72 } 73 74 // Make a retryer for Aborted and certain Internal errors. 75 retryer := onCodes(DefaultRetryBackoff, codes.Aborted, codes.Internal) 76 // Execute the PDML and retry if the transaction is aborted. 77 executePdmlWithRetry := func(ctx context.Context) (int64, error) { 78 for { 79 count, err := executePdml(ctx, sh, req) 80 if err == nil { 81 return count, nil 82 } 83 delay, shouldRetry := retryer.Retry(err) 84 if !shouldRetry { 85 return 0, err 86 } 87 if err := gax.Sleep(ctx, delay); err != nil { 88 return 0, err 89 } 90 } 91 } 92 return executePdmlWithRetry(ctx) 93} 94 95// executePdml executes the following steps: 96// 1. Begin a PDML transaction 97// 2. Add the ID of the PDML transaction to the SQL request. 98// 3. Execute the update statement on the PDML transaction 99// 100// Note that PDML transactions cannot be committed or rolled back. 101func executePdml(ctx context.Context, sh *sessionHandle, req *sppb.ExecuteSqlRequest) (count int64, err error) { 102 // Begin transaction. 103 res, err := sh.getClient().BeginTransaction(contextWithOutgoingMetadata(ctx, sh.getMetadata()), &sppb.BeginTransactionRequest{ 104 Session: sh.getID(), 105 Options: &sppb.TransactionOptions{ 106 Mode: &sppb.TransactionOptions_PartitionedDml_{PartitionedDml: &sppb.TransactionOptions_PartitionedDml{}}, 107 }, 108 }) 109 if err != nil { 110 return 0, toSpannerError(err) 111 } 112 // Add a reference to the PDML transaction on the ExecuteSql request. 113 req.Transaction = &sppb.TransactionSelector{ 114 Selector: &sppb.TransactionSelector_Id{Id: res.Id}, 115 } 116 resultSet, err := sh.getClient().ExecuteSql(contextWithOutgoingMetadata(ctx, sh.getMetadata()), req) 117 if err != nil { 118 return 0, err 119 } 120 if resultSet.Stats == nil { 121 return 0, spannerErrorf(codes.InvalidArgument, "query passed to Update: %q", req.Sql) 122 } 123 return extractRowCount(resultSet.Stats) 124} 125