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Comment:Mention the cell-overwrite optimization on the change log.
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SHA3-256: d324d1a30ebf3c711a53a8e889346dd04e45713b23c2072aaa3b96fdbfe5fef5
User & Date: drh 2018-05-08 13:35:00
More details on the UPSERT documentation. check-in: 7ca811b29f user: drh tags: trunk
Mention the cell-overwrite optimization on the change log. check-in: d324d1a30e user: drh tags: trunk
Documentation for SQLITE_ENABLE_SORTER_REFERENCES. check-in: 183931a121 user: drh tags: trunk
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    36     36   <li> The [CLI] automatically intercepts the raw [EXPLAIN QUERY PLAN] 
    37     37        output an reformats it into an ASCII-art graph.
    38     38   <li> Enhance the query planner to allow the [OR optimization] to proceed
    39     39        even if the OR expression has also been converted into an IN
    40     40        expression.  Uses of the OR optimization are now also 
    41     41        [eqp-or-opt|more clearly shown] in the [EXPLAIN QUERY PLAN] output.
    42     42   <p><b>Performance:</b>
           43  +<li> [UPDATE] avoids writing database pages that do not actually change.
           44  +     For example, "UPDATE t1 SET x=25 WHERE y=?" becomes a no-op if the
           45  +     value in column x is already 25.  Similarly, 
           46  +     when doing [UPDATE] on records that span multiple pages, only write
           47  +     the subset of pages that contain the changed value(s).
    43     48   <li> Queries that use ORDER BY and LIMIT now try to avoid computing
    44     49        rows that cannot possibly come in under the LIMIT. This can greatly
    45     50        improve performance of ORDER BY LIMIT queries, especially when the
    46     51        LIMIT is small relative to the number of unrestricted output rows.
    47     52   <li> Performance improvements in the LEMON-generated parser.
    48     53   <p><b>Bug fixes:</b>
    49     54   <li> For the right-hand table of a LEFT JOIN, compute the values