@Override
public PostgresStatementResult execute(
PostgresQueryContext context, QueryBindings bindings, int maxrows) throws IOException {
PostgresServerSession server = context.getServer();
server.getSessionMonitor().countEvent(StatementTypes.OTHER_STMT);
PostgresMessenger messenger = server.getMessenger();
ServerValueEncoder encoder = server.getValueEncoder();
int nrows = 0;
for (String row : explanation) {
messenger.beginMessage(PostgresMessages.DATA_ROW_TYPE.code());
messenger.writeShort(1);
ByteArrayOutputStream bytes = encoder.encodePObject(row, colType, false);
messenger.writeInt(bytes.size());
messenger.writeByteStream(bytes);
messenger.sendMessage();
nrows++;
if ((maxrows > 0) && (nrows >= maxrows)) break;
}
return commandComplete("EXPLAIN " + nrows, nrows);
}
@Override
public void sendDescription(PostgresQueryContext context, boolean always, boolean params)
throws IOException {
PostgresServerSession server = context.getServer();
PostgresMessenger messenger = server.getMessenger();
if (params) {
messenger.beginMessage(PostgresMessages.PARAMETER_DESCRIPTION_TYPE.code());
messenger.writeShort(0);
messenger.sendMessage();
}
messenger.beginMessage(PostgresMessages.ROW_DESCRIPTION_TYPE.code());
messenger.writeShort(1);
messenger.writeString(colName); // attname
messenger.writeInt(0); // attrelid
messenger.writeShort(0); // attnum
messenger.writeInt(colType.getOid()); // atttypid
messenger.writeShort(colType.getLength()); // attlen
messenger.writeInt(colType.getModifier()); // atttypmod
messenger.writeShort(0);
messenger.sendMessage();
}
@Override
public PostgresStatement finishGenerating(
PostgresServerSession server,
String sql,
StatementNode stmt,
List<ParameterNode> params,
int[] paramTypes) {
ExplainPlanContext context = new ExplainPlanContext(compiler, new PostgresQueryContext(server));
ExplainStatementNode explainStmt = (ExplainStatementNode) stmt;
StatementNode innerStmt = explainStmt.getStatement();
if (params == null) params = new ParameterFinder().find(innerStmt);
Explainable explainable;
if (innerStmt instanceof CallStatementNode) {
explainable =
PostgresCallStatementGenerator.explainable(
server, (CallStatementNode) innerStmt, params, paramTypes);
} else {
BasePlannable result = compiler.compile((DMLStatementNode) innerStmt, params, context);
explainable = result.getPlannable();
}
List<String> explain;
if (compiler instanceof PostgresJsonCompiler) {
JsonFormatter f = new JsonFormatter();
explain =
Collections.singletonList(
f.format(explainable.getExplainer(context.getExplainContext())));
} else {
DefaultFormatter.LevelOfDetail detail;
switch (explainStmt.getDetail()) {
case BRIEF:
detail = DefaultFormatter.LevelOfDetail.BRIEF;
break;
default:
case NORMAL:
detail = DefaultFormatter.LevelOfDetail.NORMAL;
break;
case VERBOSE:
detail = DefaultFormatter.LevelOfDetail.VERBOSE;
break;
}
DefaultFormatter f = new DefaultFormatter(server.getDefaultSchemaName(), detail);
explain = f.format(explainable.getExplainer(context.getExplainContext()));
}
init(explain);
compiler = null;
return this;
}
