Remove WITH OIDS support, change oid catalog column visibility.

Previously tables declared WITH OIDS, including a significant fraction
of the catalog tables, stored the oid column not as a normal column,
but as part of the tuple header.

This special column was not shown by default, which was somewhat odd,
as it's often (consider e.g. pg_class.oid) one of the more important
parts of a row.  Neither pg_dump nor COPY included the contents of the
oid column by default.

The fact that the oid column was not an ordinary column necessitated a
significant amount of special case code to support oid columns. That
already was painful for the existing, but upcoming work aiming to make
table storage pluggable, would have required expanding and duplicating
that "specialness" significantly.

WITH OIDS has been deprecated since 2005 (commit ff02d0a05280e0).
Remove it.

Removing includes:
- CREATE TABLE and ALTER TABLE syntax for declaring the table to be
  WITH OIDS has been removed (WITH (oids[ = true]) will error out)
- pg_dump does not support dumping tables declared WITH OIDS and will
  issue a warning when dumping one (and ignore the oid column).
- restoring an pg_dump archive with pg_restore will warn when
  restoring a table with oid contents (and ignore the oid column)
- COPY will refuse to load binary dump that includes oids.
- pg_upgrade will error out when encountering tables declared WITH
  OIDS, they have to be altered to remove the oid column first.
- Functionality to access the oid of the last inserted row (like
  plpgsql's RESULT_OID, spi's SPI_lastoid, ...) has been removed.

The syntax for declaring a table WITHOUT OIDS (or WITH (oids = false)
for CREATE TABLE) is still supported. While that requires a bit of
support code, it seems unnecessary to break applications / dumps that
do not use oids, and are explicit about not using them.

The biggest user of WITH OID columns was postgres' catalog. This
commit changes all 'magic' oid columns to be columns that are normally
declared and stored. To reduce unnecessary query breakage all the
newly added columns are still named 'oid', even if a table's column
naming scheme would indicate 'reloid' or such.  This obviously
requires adapting a lot code, mostly replacing oid access via
HeapTupleGetOid() with access to the underlying Form_pg_*->oid column.

The bootstrap process now assigns oids for all oid columns in
genbki.pl that do not have an explicit value (starting at the largest
oid previously used), only oids assigned later by oids will be above
FirstBootstrapObjectId. As the oid column now is a normal column the
special bootstrap syntax for oids has been removed.

Oids are not automatically assigned during insertion anymore, all
backend code explicitly assigns oids with GetNewOidWithIndex(). For
the rare case that insertions into the catalog via SQL are called for
the new pg_nextoid() function can be used (which only works on catalog
tables).

The fact that oid columns on system tables are now normal columns
means that they will be included in the set of columns expanded
by * (i.e. SELECT * FROM pg_class will now include the table's oid,
previously it did not). It'd not technically be hard to hide oid
column by default, but that'd mean confusing behavior would either
have to be carried forward forever, or it'd cause breakage down the
line.

While it's not unlikely that further adjustments are needed, the
scope/invasiveness of the patch makes it worthwhile to get merge this
now. It's painful to maintain externally, too complicated to commit
after the code code freeze, and a dependency of a number of other
patches.

Catversion bump, for obvious reasons.

Author: Andres Freund, with contributions by John Naylor
Discussion: https://postgr.es/m/20180930034810.ywp2c7awz7opzcfr@alap3.anarazel.de

1 files changed, 15 insertions, 127 deletions

diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index a283fcb33ad..4aa8890fe81 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -131,7 +131,6 @@ typedef struct CopyStateData
 	bool		is_program;		/* is 'filename' a program to popen? */
 	copy_data_source_cb data_source_cb; /* function for reading data */
 	bool		binary;			/* binary format? */
-	bool		oids;			/* include OIDs? */
 	bool		freeze;			/* freeze rows on loading? */
 	bool		csv_mode;		/* Comma Separated Value format? */
 	bool		header_line;	/* CSV header line? */
@@ -173,7 +172,6 @@ typedef struct CopyStateData
 	 * Working state for COPY FROM
 	 */
 	AttrNumber	num_defaults;
-	bool		file_has_oids;
 	FmgrInfo	oid_in_function;
 	Oid			oid_typioparam;
 	FmgrInfo   *in_functions;	/* array of input functions for each attrs */
@@ -313,7 +311,7 @@ static CopyState BeginCopyTo(ParseState *pstate, Relation rel, RawStmt *query,
 static void EndCopyTo(CopyState cstate);
 static uint64 DoCopyTo(CopyState cstate);
 static uint64 CopyTo(CopyState cstate);
-static void CopyOneRowTo(CopyState cstate, Oid tupleOid,
+static void CopyOneRowTo(CopyState cstate,
 			 Datum *values, bool *nulls);
 static void CopyFromInsertBatch(CopyState cstate, EState *estate,
 					CommandId mycid, int hi_options,
@@ -1086,15 +1084,6 @@ ProcessCopyOptions(ParseState *pstate,
 						 errmsg("COPY format \"%s\" not recognized", fmt),
 						 parser_errposition(pstate, defel->location)));
 		}
-		else if (strcmp(defel->defname, "oids") == 0)
-		{
-			if (cstate->oids)
-				ereport(ERROR,
-						(errcode(ERRCODE_SYNTAX_ERROR),
-						 errmsg("conflicting or redundant options"),
-						 parser_errposition(pstate, defel->location)));
-			cstate->oids = defGetBoolean(defel);
-		}
 		else if (strcmp(defel->defname, "freeze") == 0)
 		{
 			if (cstate->freeze)
@@ -1440,13 +1429,6 @@ BeginCopy(ParseState *pstate,
 		cstate->rel = rel;
 
 		tupDesc = RelationGetDescr(cstate->rel);
-
-		/* Don't allow COPY w/ OIDs to or from a table without them */
-		if (cstate->oids && !cstate->rel->rd_rel->relhasoids)
-			ereport(ERROR,
-					(errcode(ERRCODE_UNDEFINED_COLUMN),
-					 errmsg("table \"%s\" does not have OIDs",
-							RelationGetRelationName(cstate->rel))));
 	}
 	else
 	{
@@ -1458,12 +1440,6 @@ BeginCopy(ParseState *pstate,
 		Assert(!is_from);
 		cstate->rel = NULL;
 
-		/* Don't allow COPY w/ OIDs from a query */
-		if (cstate->oids)
-			ereport(ERROR,
-					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-					 errmsg("COPY (query) WITH OIDS is not supported")));
-
 		/*
 		 * Run parse analysis and rewrite.  Note this also acquires sufficient
 		 * locks on the source table(s).
@@ -2028,8 +2004,6 @@ CopyTo(CopyState cstate)
 		CopySendData(cstate, BinarySignature, 11);
 		/* Flags field */
 		tmp = 0;
-		if (cstate->oids)
-			tmp |= (1 << 16);
 		CopySendInt32(cstate, tmp);
 		/* No header extension */
 		tmp = 0;
@@ -2091,7 +2065,7 @@ CopyTo(CopyState cstate)
 			heap_deform_tuple(tuple, tupDesc, values, nulls);
 
 			/* Format and send the data */
-			CopyOneRowTo(cstate, HeapTupleGetOid(tuple), values, nulls);
+			CopyOneRowTo(cstate, values, nulls);
 			processed++;
 		}
 
@@ -2124,7 +2098,7 @@ CopyTo(CopyState cstate)
  * Emit one row during CopyTo().
  */
 static void
-CopyOneRowTo(CopyState cstate, Oid tupleOid, Datum *values, bool *nulls)
+CopyOneRowTo(CopyState cstate, Datum *values, bool *nulls)
 {
 	bool		need_delim = false;
 	FmgrInfo   *out_functions = cstate->out_functions;
@@ -2139,25 +2113,6 @@ CopyOneRowTo(CopyState cstate, Oid tupleOid, Datum *values, bool *nulls)
 	{
 		/* Binary per-tuple header */
 		CopySendInt16(cstate, list_length(cstate->attnumlist));
-		/* Send OID if wanted --- note attnumlist doesn't include it */
-		if (cstate->oids)
-		{
-			/* Hack --- assume Oid is same size as int32 */
-			CopySendInt32(cstate, sizeof(int32));
-			CopySendInt32(cstate, tupleOid);
-		}
-	}
-	else
-	{
-		/* Text format has no per-tuple header, but send OID if wanted */
-		/* Assume digits don't need any quoting or encoding conversion */
-		if (cstate->oids)
-		{
-			string = DatumGetCString(DirectFunctionCall1(oidout,
-														 ObjectIdGetDatum(tupleOid)));
-			CopySendString(cstate, string);
-			need_delim = true;
-		}
 	}
 
 	foreach(cur, cstate->attnumlist)
@@ -2689,7 +2644,6 @@ CopyFrom(CopyState cstate)
 	{
 		TupleTableSlot *slot;
 		bool		skip_tuple;
-		Oid			loaded_oid = InvalidOid;
 
 		CHECK_FOR_INTERRUPTS();
 
@@ -2706,15 +2660,12 @@ CopyFrom(CopyState cstate)
 		/* Switch into its memory context */
 		MemoryContextSwitchTo(GetPerTupleMemoryContext(estate));
 
-		if (!NextCopyFrom(cstate, econtext, values, nulls, &loaded_oid))
+		if (!NextCopyFrom(cstate, econtext, values, nulls))
 			break;
 
 		/* And now we can form the input tuple. */
 		tuple = heap_form_tuple(tupDesc, values, nulls);
 
-		if (loaded_oid != InvalidOid)
-			HeapTupleSetOid(tuple, loaded_oid);
-
 		/*
 		 * Constraints might reference the tableoid column, so initialize
 		 * t_tableOid before evaluating them.
@@ -3368,12 +3319,7 @@ BeginCopyFrom(ParseState *pstate,
 		}
 	}
 
-	if (!cstate->binary)
-	{
-		/* must rely on user to tell us... */
-		cstate->file_has_oids = cstate->oids;
-	}
-	else
+	if (cstate->binary)
 	{
 		/* Read and verify binary header */
 		char		readSig[11];
@@ -3390,7 +3336,10 @@ BeginCopyFrom(ParseState *pstate,
 			ereport(ERROR,
 					(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
 					 errmsg("invalid COPY file header (missing flags)")));
-		cstate->file_has_oids = (tmp & (1 << 16)) != 0;
+		if ((tmp & (1 << 16)) != 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
+					 errmsg("invalid COPY file header (WITH OIDS)")));
 		tmp &= ~(1 << 16);
 		if ((tmp >> 16) != 0)
 			ereport(ERROR,
@@ -3412,21 +3361,13 @@ BeginCopyFrom(ParseState *pstate,
 		}
 	}
 
-	if (cstate->file_has_oids && cstate->binary)
-	{
-		getTypeBinaryInputInfo(OIDOID,
-							   &in_func_oid, &cstate->oid_typioparam);
-		fmgr_info(in_func_oid, &cstate->oid_in_function);
-	}
-
 	/* create workspace for CopyReadAttributes results */
 	if (!cstate->binary)
 	{
 		AttrNumber	attr_count = list_length(cstate->attnumlist);
-		int			nfields = cstate->file_has_oids ? (attr_count + 1) : attr_count;
 
-		cstate->max_fields = nfields;
-		cstate->raw_fields = (char **) palloc(nfields * sizeof(char *));
+		cstate->max_fields = attr_count;
+		cstate->raw_fields = (char **) palloc(attr_count * sizeof(char *));
 	}
 
 	MemoryContextSwitchTo(oldcontext);
@@ -3499,7 +3440,7 @@ NextCopyFromRawFields(CopyState cstate, char ***fields, int *nfields)
  */
 bool
 NextCopyFrom(CopyState cstate, ExprContext *econtext,
-			 Datum *values, bool *nulls, Oid *tupleOid)
+			 Datum *values, bool *nulls)
 {
 	TupleDesc	tupDesc;
 	AttrNumber	num_phys_attrs,
@@ -3508,16 +3449,12 @@ NextCopyFrom(CopyState cstate, ExprContext *econtext,
 	FmgrInfo   *in_functions = cstate->in_functions;
 	Oid		   *typioparams = cstate->typioparams;
 	int			i;
-	int			nfields;
-	bool		isnull;
-	bool		file_has_oids = cstate->file_has_oids;
 	int		   *defmap = cstate->defmap;
 	ExprState **defexprs = cstate->defexprs;
 
 	tupDesc = RelationGetDescr(cstate->rel);
 	num_phys_attrs = tupDesc->natts;
 	attr_count = list_length(cstate->attnumlist);
-	nfields = file_has_oids ? (attr_count + 1) : attr_count;
 
 	/* Initialize all values for row to NULL */
 	MemSet(values, 0, num_phys_attrs * sizeof(Datum));
@@ -3536,41 +3473,13 @@ NextCopyFrom(CopyState cstate, ExprContext *econtext,
 			return false;
 
 		/* check for overflowing fields */
-		if (nfields > 0 && fldct > nfields)
+		if (attr_count > 0 && fldct > attr_count)
 			ereport(ERROR,
 					(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
 					 errmsg("extra data after last expected column")));
 
 		fieldno = 0;
 
-		/* Read the OID field if present */
-		if (file_has_oids)
-		{
-			if (fieldno >= fldct)
-				ereport(ERROR,
-						(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
-						 errmsg("missing data for OID column")));
-			string = field_strings[fieldno++];
-
-			if (string == NULL)
-				ereport(ERROR,
-						(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
-						 errmsg("null OID in COPY data")));
-			else if (cstate->oids && tupleOid != NULL)
-			{
-				cstate->cur_attname = "oid";
-				cstate->cur_attval = string;
-				*tupleOid = DatumGetObjectId(DirectFunctionCall1(oidin,
-																 CStringGetDatum(string)));
-				if (*tupleOid == InvalidOid)
-					ereport(ERROR,
-							(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
-							 errmsg("invalid OID in COPY data")));
-				cstate->cur_attname = NULL;
-				cstate->cur_attval = NULL;
-			}
-		}
-
 		/* Loop to read the user attributes on the line. */
 		foreach(cur, cstate->attnumlist)
 		{
@@ -3628,7 +3537,7 @@ NextCopyFrom(CopyState cstate, ExprContext *econtext,
 			cstate->cur_attval = NULL;
 		}
 
-		Assert(fieldno == nfields);
+		Assert(fieldno == attr_count);
 	}
 	else
 	{
@@ -3674,27 +3583,6 @@ NextCopyFrom(CopyState cstate, ExprContext *econtext,
 					 errmsg("row field count is %d, expected %d",
 							(int) fld_count, attr_count)));
 
-		if (file_has_oids)
-		{
-			Oid			loaded_oid;
-
-			cstate->cur_attname = "oid";
-			loaded_oid =
-				DatumGetObjectId(CopyReadBinaryAttribute(cstate,
-														 0,
-														 &cstate->oid_in_function,
-														 cstate->oid_typioparam,
-														 -1,
-														 &isnull));
-			if (isnull || loaded_oid == InvalidOid)
-				ereport(ERROR,
-						(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
-						 errmsg("invalid OID in COPY data")));
-			cstate->cur_attname = NULL;
-			if (cstate->oids && tupleOid != NULL)
-				*tupleOid = loaded_oid;
-		}
-
 		i = 0;
 		foreach(cur, cstate->attnumlist)
 		{
@@ -5022,7 +4910,7 @@ copy_dest_receive(TupleTableSlot *slot, DestReceiver *self)
 	slot_getallattrs(slot);
 
 	/* And send the data */
-	CopyOneRowTo(cstate, InvalidOid, slot->tts_values, slot->tts_isnull);
+	CopyOneRowTo(cstate, slot->tts_values, slot->tts_isnull);
 	myState->processed++;
 
 	return true;