Log Message:
Release 3.18.0:

Added the PRAGMA optimize command
The SQLite version identifier returned by the sqlite_source_id() SQL function \ 
and the sqlite3_sourceid() C API and found in the SQLITE_SOURCE_ID macro is now \ 
a 64-digit SHA3-256 hash instead of a 40-digit SHA1 hash.
Added the json_patch() SQL function to the JSON1 extension.
Enhance the LIKE optimization so that it works for arbitrary expressions on the \ 
left-hand side as long as the LIKE pattern on the right-hand side does not begin \ 
with a digit or minus sign.
Added the sqlite3_set_last_insert_rowid() interface and use the new interface in \ 
the FTS3, FTS4, and FTS5 extensions to ensure that the \ 
sqlite3_last_insert_rowid() interface always returns reasonable values.
Enhance PRAGMA integrity_check and PRAGMA quick_check so that they verify CHECK \ 
constraints.
Enhance the query plans for joins to detect empty tables early and halt without \ 
doing unnecessary work.
Enhance the sqlite3_mprintf() family of interfaces and the printf SQL function \ 
to put comma separators at the thousands marks for integers, if the \ 
"," format modifier is used in between the "%" and the \ 
"d" (example: "%,d").
Added the -DSQLITE_MAX_MEMORY=N compile-time option.
Added the .sha3sum dot-command and the .selftest dot-command to the command-line \ 
shell
Begin enforcing SQLITE_LIMIT_VDBE_OP. This can be used, for example, to prevent \ 
excessively large prepared statements in systems that accept SQL queries from \ 
untrusted users.
Various performance improvements.

Bug Fixes:
----------
Ensure that indexed expressions with collating sequences are handled correctly. \ 
Fix for ticket eb703ba7b50c1a5.
Fix a bug in the 'start of ...' modifiers for the date and time functions. \ 
Ticket 6097cb92745327a1
Fix a potential segfault in complex recursive triggers, resulting from a bug in \ 
the OP_Once opcode introduced as part of a performance optimization in version \ 
3.15.0. Ticket 06796225f59c057c
In the RBU extension, add extra sync operations to avoid the possibility of \ 
corruption following a power failure.
The sqlite3_trace_v2() output for nested SQL statements should always begin with \ 
a "--" comment marker.