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Software update: SQLite 3.24.0

 SQLite logo (80 pix) SQLite is a database system developed in C that can be used as a database for websites and embedded applications. According to the developers, SQLite does not need installation and administration, it supports databases up to a size of two terabytes and a complete database is stored in one file. Furthermore, almost supports the complete SQL92 specification and is easy to control via Tcl / Tk . The developer has released version 3.24.0 with the following list of modifications:

SQLite Release 3.24.0
CLI Enhancements:

  • Automatically intercepts the raw EXPLAIN QUERY PLAN output and reformat it into an ASCII art graph.
  • Lines that begin with “#” and that are not in the middle of an SQL statement are interpreted as comments.
  • Added the –append option to the “. backup “command
  • Added the” .dbconfig “command

Performance:

  • UPDATE avoids unnecessary low-level disk writes when the contents of the database do not actually change. For example, “UPDATE t1 SET x = 25 WHERE y =?” generates no extra disk I / O if the value in column x is already 25. Similarly, when doing UPDATE on records that span multiple pages, only the subset of pages that actually change are written to disk. This is a low-level performance optimization and does not affect the behavior of TRIGGERs or other higher-level SQL structures
  • Queries that use ORDER BY and LIMIT. This can be improved or ORDER BY LIMIT queries, especially when the LIMIT is small relative to the number of unrestricted output rows.
  • The OR optimization is allowed to proceed even if the OR has been converted into an IN expression. Uses of the OR are now also more clearly shown in the EXPLAIN QUERY PLAN output.
  • The query planner is more aggressive about using automatic indexes for views and subqueries for which it is not possible to create a persistent index.
  • Make-up of the one-pass UPDATE and DELETE query plans in the R-Tree extension where appropriate.
  • Performance improvements in the LEMON-generated parser

Bug fixes:

  • For the right-hand table of a LEFT JOIN, compute the values ​​of expressions directly rather than loading precomputed values ​​out of an expression index the expression index could not contain the correct value. Ticket 7fa8049685b50b5aeb0c2
  • Do not attempt to use the WHERE clause to enable indexed lookup of the right-hand table of a LEFT JOIN. Ticket 4ba5abf65c5b0f9a96a7a
  • Fix a memory leak that can occur in the CSV virtual table
  • Fix a long-standing problem where a corrupt schema on the sqlite_sequence table used by AUTOINCREMENT can lead to a crash. Ticket d8dc2b3a58cd5dc2918a1
  • Fix the json_each () function so that it returns valid results on its “full-key” column when the input is a simple value rather than an array or object. [19659021] SQLite screenshot ” width=”620″ height=”353″/>

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