ISqlDialect gains MaxBindParameters — the per-command ceiling the seam was
missing while modelling everything else that differs per backend: 2098 usable
of SQL Server's 2100 (sp_executesql spends two), 1000 for Oracle's IN-list
limit (ORA-01795, tighter than its 64k bind count), 65535 for the Postgres
Bind message.
SqlGroupPlanner.AddKeyValuePlans now emits several plans for one group when
its distinct keys exceed that ceiling, instead of one statement the provider
refuses after the connection opened — which left every tag in an EAV group
publishing BadCommunicationError on every poll, permanently, and reported the
database endpoint as down. Chunks share the group key; members follow their
own key so a shared keyValue never splits. SqlPollReader is unchanged: it runs
one command per plan and slices each plan's own Members back, proven by a
fixture read at a ceiling of 1.
NAMEDATALEN-1 (63) and Oracle 12.2's 128 are byte limits in the database
encoding, not character counts, so a 32-character Cyrillic name passed
ident.Length and was then silently truncated (Postgres) or rejected by the
server (Oracle). Both dialects now measure Encoding.UTF8.GetByteCount and say
'bytes' in the rejection. SqlServerDialect deliberately keeps ident.Length —
sysname is nvarchar(128), a real character limit — pinned by a control test.
Joseph Doherty