It's possible to define a type (e.g., an enum) with the same name in two
different schemas. When initializing data types after connecting, types
defined within schemas other than pg_catalog or public should be
qualified with their schema name to disambiguate them and ensure all
types with the same base name get added to the map of OID to type.
Prior to this commit, the last type scanned would "win", and all others
with the same name would be missing from the ConnInfo type maps, which
would subsequently cause any PREPARE involving columns of those missing
types to return the error "unknown oid".
Prior to this commit, execEx() would write the one round trip exec to
the connection before first calling ensureConnectionReadyForQuery, which
ultimately caused any errors to be suppressed if the exec followed a
valid query, because the receive message processing would finish
successfully as soon as it received the ReadyForQuery that actually
belonged to the preceding query. So, the exec would never actually
receive the error message that it caused, leaving it to be incorrectly
received by the first subsequent query sent.
This replaces *Conn.CopyTo. CopyTo was named incorrectly. In PostgreSQL
COPY FROM is the command that copies from the client to the server. In
addition, CopyTo does not accept a schema qualified table name. This
commit introduces the Identifier type which handles multi-part names and
correctly quotes/sanitizes them. The new CopyFrom method uses this
Identifier type.
Conn.CopyTo is deprecated.
refs #243 and #190
Though this doesn't follow Go naming conventions exactly it makes names more
consistent with PostgreSQL and it is easier to read. For example, TIDOID becomes
TidOid. In addition this is one less breaking change in the move to V3.
This should substantially reduce memory allocations and memory copies.
It also means that PostgreSQL messages are always entirely buffered in memory
before processing begins. This simplifies the message processing code.
In particular, Conn.WaitForNotification is dramatically simplified by this
change.
