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Project 4

讲义​

Gitbook​

简书​

视频​

博客​

Github​

实现​

Delete​

bustub> explain delete from t1 where v1 = 1;
 === BINDER ===                                                          
 Delete { table=BoundBaseTableRef { table=t1, oid=22 }, expr=(t1.v1=1) } 
 === PLANNER ===                                                         
 Delete { table_oid=22 } | (__bustub_internal.delete_rows:INTEGER)       
   Filter { predicate=(#0.0=1) } | (t1.v1:INTEGER)                       
     SeqScan { table=t1 } | (t1.v1:INTEGER)                              
 === OPTIMIZER ===                                                       
 Delete { table_oid=22 } | (__bustub_internal.delete_rows:INTEGER)       
   SeqScan { table=t1, filter=(#0.0=1) } | (t1.v1:INTEGER)

Index​

CREATE TABLE nft(id INT, terrier INT);
CREATE INDEX nftid ON nft(id);
INSERT INTO nft VALUES (0, 0), (1, 1);
EXPLAIN UPDATE nft SET terrier = 2 WHERE id = 1;
EXPLAIN SELECT * FROM nft WHERE id = 1;
EXPLAIN SELECT * FROM nft;
SELECT * FROM nft WHERE id = 1;

Q&A​

1. For an insert operation, what should we locked? The rid is determined after the insert.​

You can first insert then lock. This is a long-term bug to be fixed.

2. Halloween problem​