7592f52d2e
## Proposed changes Add transaction for the operation of insert. It will cost less time than non-transaction(it will cost 1/1000 time) when you want to insert a amount of rows. ### Syntax ``` BEGIN [ WITH LABEL label]; INSERT INTO table_name ... [COMMIT | ROLLBACK]; ``` ### Example commit a transaction: ``` begin; insert into Tbl values(11, 22, 33); commit; ``` rollback a transaction: ``` begin; insert into Tbl values(11, 22, 33); rollback; ``` commit a transaction with label: ``` begin with label test_label; insert into Tbl values(11, 22, 33); commit; ``` ### Description ``` begin: begin a transaction, the next insert will execute in the transaction until commit/rollback; commit: commit the transaction, the data in the transaction will be inserted into the table; rollback: abort the transaction, nothing will be inserted into the table; ``` ### The main realization principle: ``` 1. begin a transaction in the session. next sql is executed in the transaction; 2. insert sql will be parser and get the database name and table name, they will be used to select a be and create a pipe to accept data; 3. all inserted values will be sent to the be and write into the pipe; 4. a thread will get the data from the pipe, then write them to disk; 5. commit will complete this transaction and make these data visible; 6. rollback will abort this transaction ``` ### Some restrictions on the use of update syntax. 1. Only ```insert``` can be called in a transaction. 2. If something error happened, ```commit``` will not succeed, it will ```rollback``` directly; 3. By default, if part of insert in the transaction is invalid, ```commit``` will only insert the other correct data into the table. 4. If you need ```commit``` return failed when any insert in the transaction is invalid, you need execute ```set enable_insert_strict = true``` before ```begin```.
41 lines
1.2 KiB
C++
41 lines
1.2 KiB
C++
// Licensed to the Apache Software Foundation (ASF) under one
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// or more contributor license agreements. See the NOTICE file
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// distributed with this work for additional information
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// regarding copyright ownership. The ASF licenses this file
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// to you under the Apache License, Version 2.0 (the
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// "License"); you may not use this file except in compliance
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// with the License. You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing,
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// software distributed under the License is distributed on an
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// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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// KIND, either express or implied. See the License for the
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// specific language governing permissions and limitations
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// under the License.
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#pragma once
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#include "exec/line_reader.h"
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namespace doris {
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class FileReader;
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class PlainBinaryLineReader : public LineReader {
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public:
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PlainBinaryLineReader(FileReader* file_reader);
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virtual ~PlainBinaryLineReader();
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virtual Status read_line(const uint8_t** ptr, size_t* size, bool* eof) override;
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virtual void close() override;
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private:
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FileReader* _file_reader;
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};
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} // namespace doris
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