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 RequestOptions: createRequestOptions(options.Priority, options.RequestTag, ""), 73 } 74 75 // Make a retryer for Aborted and certain Internal errors. 76 retryer := onCodes(DefaultRetryBackoff, codes.Aborted, codes.Internal) 77 // Execute the PDML and retry if the transaction is aborted. 78 executePdmlWithRetry := func(ctx context.Context) (int64, error) { 79 for { 80 count, err := executePdml(ctx, sh, req) 81 if err == nil { 82 return count, nil 83 } 84 delay, shouldRetry := retryer.Retry(err) 85 if !shouldRetry { 86 return 0, err 87 } 88 if err := gax.Sleep(ctx, delay); err != nil { 89 return 0, err 90 } 91 } 92 } 93 return executePdmlWithRetry(ctx) 94} 95 96// executePdml executes the following steps: 97// 1. Begin a PDML transaction 98// 2. Add the ID of the PDML transaction to the SQL request. 99// 3. Execute the update statement on the PDML transaction 100// 101// Note that PDML transactions cannot be committed or rolled back. 102func executePdml(ctx context.Context, sh *sessionHandle, req *sppb.ExecuteSqlRequest) (count int64, err error) { 103 // Begin transaction. 104 res, err := sh.getClient().BeginTransaction(contextWithOutgoingMetadata(ctx, sh.getMetadata()), &sppb.BeginTransactionRequest{ 105 Session: sh.getID(), 106 Options: &sppb.TransactionOptions{ 107 Mode: &sppb.TransactionOptions_PartitionedDml_{PartitionedDml: &sppb.TransactionOptions_PartitionedDml{}}, 108 }, 109 }) 110 if err != nil { 111 return 0, ToSpannerError(err) 112 } 113 // Add a reference to the PDML transaction on the ExecuteSql request. 114 req.Transaction = &sppb.TransactionSelector{ 115 Selector: &sppb.TransactionSelector_Id{Id: res.Id}, 116 } 117 resultSet, err := sh.getClient().ExecuteSql(contextWithOutgoingMetadata(ctx, sh.getMetadata()), req) 118 if err != nil { 119 return 0, err 120 } 121 if resultSet.Stats == nil { 122 return 0, spannerErrorf(codes.InvalidArgument, "query passed to Update: %q", req.Sql) 123 } 124 return extractRowCount(resultSet.Stats) 125} 126