delete postgresql

src/Makefile.am

@@ -123,11 +123,7 @@ main/StellarCoreVersion.cpp: always
 	@if cmp -s $@~ $@; then rm -f $@~; else \
 	    mv -f $@~ $@ && printf "echo '%s' > $@\n" "$$(cat $@)"; fi
 
-if USE_POSTGRES
-TESTS=test/selftest-pg
-else # !USE_POSTGRES
 TESTS=test/selftest-nopg
-endif # !USE_POSTGRES
 TESTS += test/check-nondet
 
 format: always

src/bucket/readme.md

@@ -38,12 +38,11 @@ receives a single large, atomic write whenever a ledger closes and many
 reads during consensus. There is never a write during a read, so all the reads occur on an
 effectively
 immutable database. This write once read many times paradigm is suited better for a LSM structure
-(the bucket list) than SQL DBs. In particular, Postgres is ACID compliant and supports
-transactions that can be rolled back. This introduces significant, unnecessary overhead.
+(the bucket list) than SQL DBs. 
 Since our access pattern never has conflicting reads and writes, ACID compliance is not required.
 Additionally, the current core implementation never rolls back a SQL transaction. Finally,
 all reads occur on an immutable database, opening the door for parallelism.
-However, MySQL and Postgres do not treat the DB as immutable during reads
+However, SQL DBs do not treat the DB as immutable during reads
 and cannot take advantage of this parallelism.
 
 By performing key-value lookup directly on the BucketList, we can remove ACID/rollback overhead,

src/bucket/test/BucketTests.cpp

@@ -987,10 +987,4 @@ TEST_CASE("bucket apply bench", "[bucketbench][!hide]")
     {
         runtest(Config::TESTDB_ON_DISK_SQLITE);
     }
-#ifdef USE_POSTGRES
-    SECTION("postgresql")
-    {
-        runtest(Config::TESTDB_POSTGRESQL);
-    }
-#endif
 }

src/database/Database.cpp

@@ -38,9 +38,6 @@
 
 #include <lib/soci/src/backends/sqlite3/soci-sqlite3.h>
 #include <string>
-#ifdef USE_POSTGRES
-#include <lib/soci/src/backends/postgresql/soci-postgresql.h>
-#endif
 #include <sstream>
 #include <stdexcept>
 #include <thread>
@@ -75,31 +72,6 @@ static int const MIN_SQLITE_MINOR_VERSION = 45;
 static int const MIN_SQLITE_VERSION =
     (1000000 * MIN_SQLITE_MAJOR_VERSION) + (1000 * MIN_SQLITE_MINOR_VERSION);
 
-// PostgreSQL pre-10.0 actually used its "minor number" as a major one
-// (meaning: 9.4 and 9.5 were considered different major releases, with
-// compatibility differences and so forth). After 10.0 they started doing
-// what everyone else does, where 10.0 and 10.1 were only "minor". Either
-// way though, we have a minimum minor version.
-static int const MIN_POSTGRESQL_MAJOR_VERSION = 9;
-static int const MIN_POSTGRESQL_MINOR_VERSION = 5;
-static int const MIN_POSTGRESQL_VERSION =
-    (10000 * MIN_POSTGRESQL_MAJOR_VERSION) +
-    (100 * MIN_POSTGRESQL_MINOR_VERSION);
-
-#ifdef USE_POSTGRES
-static std::string
-badPgVersion(int vers)
-{
-    std::ostringstream msg;
-    int maj = (vers / 10000);
-    int min = (vers - (maj * 10000)) / 100;
-    msg << "PostgreSQL version " << maj << '.' << min
-        << " is too old, must use at least " << MIN_POSTGRESQL_MAJOR_VERSION
-        << '.' << MIN_POSTGRESQL_MINOR_VERSION;
-    return msg.str();
-}
-#endif
-
 static std::string
 badSqliteVersion(int vers)
 {
@@ -118,9 +90,6 @@ Database::registerDrivers()
     if (!gDriversRegistered)
     {
         register_factory_sqlite3();
-#ifdef USE_POSTGRES
-        register_factory_postgresql();
-#endif
         gDriversRegistered = true;
     }
 }
@@ -165,20 +134,6 @@ class DatabaseConfigureSessionOp : public DatabaseTypeSpecificOperation<void>
         // Register the sqlite carray() extension we use for bulk operations.
         sqlite3_carray_init(sq->conn_, nullptr, nullptr);
     }
-#ifdef USE_POSTGRES
-    void
-    doPostgresSpecificOperation(soci::postgresql_session_backend* pg) override
-    {
-        int vers = PQserverVersion(pg->conn_);
-        if (vers < MIN_POSTGRESQL_VERSION)
-        {
-            throw std::runtime_error(badPgVersion(vers));
-        }
-        mSession
-            << "SET SESSION CHARACTERISTICS AS TRANSACTION ISOLATION LEVEL "
-               "SERIALIZABLE";
-    }
-#endif
 };
 
 Database::Database(Application& app)
@@ -381,38 +336,13 @@ Database::getUpsertTimer(std::string const& entityName)
         .TimeScope();
 }
 
-void
-Database::setCurrentTransactionReadOnly()
-{
-    if (!isSqlite())
-    {
-        auto prep = getPreparedStatement("SET TRANSACTION READ ONLY");
-        auto& st = prep.statement();
-        st.define_and_bind();
-        st.execute(false);
-    }
-}
-
 bool
 Database::isSqlite() const
 {
     return mApp.getConfig().DATABASE.value.find("sqlite3://") !=
            std::string::npos;
 }
 
-std::string
-Database::getSimpleCollationClause() const
-{
-    if (isSqlite())
-    {
-        return "";
-    }
-    else
-    {
-        return " COLLATE \"C\" ";
-    }
-}
-
 bool
 Database::canUsePool() const
 {

src/database/Database.h

@@ -64,10 +64,9 @@ class StatementContext : NonCopyable
  * Object that owns the database connection(s) that an application
  * uses to store the current ledger and other persistent state in.
  *
- * This may represent an in-memory SQLite instance (for testing), an on-disk
- * SQLite instance (for running a minimal, self-contained server) or a
- * connection to a local Postgresql database, that the node operator must have
- * set up on their own.
+ * This may represent an in-memory SQLite instance (for testing), or an on-disk
+ * SQLite instance (for running a minimal, self-contained server) that the node 
+ * operator must have set up on their own.
  *
  * Database connects, on construction, to the target specified by the
  * application Config object's Config::DATABASE value; this originates from the
@@ -81,8 +80,7 @@ class StatementContext : NonCopyable
  * worker thread.
  *
  * All database connections and transactions are set to snapshot isolation level
- * (SQL isolation level 'SERIALIZABLE' in Postgresql and Sqlite, neither of
- * which provide true serializability).
+ * (unlike SQL isolation level 'SERIALIZABLE' in Sqlite, which does not provides true serializability).
  */
 class Database : NonMovableOrCopyable
 {
@@ -134,21 +132,9 @@ class Database : NonMovableOrCopyable
     medida::TimerContext getUpdateTimer(std::string const& entityName);
     medida::TimerContext getUpsertTimer(std::string const& entityName);
 
-    // If possible (i.e. "on postgres") issue an SQL pragma that marks
-    // the current transaction as read-only. The effects of this last
-    // only as long as the current SQL transaction.
-    void setCurrentTransactionReadOnly();
-
     // Return true if the Database target is SQLite, otherwise false.
     bool isSqlite() const;
 
-    // Return an optional SQL COLLATION clause to use for text-typed columns in
-    // this database, in order to ensure they're compared "simply" using
-    // byte-value comparisons, i.e. in a non-language-sensitive fashion.  For
-    // Postgresql this will be 'COLLATE "C"' and for SQLite, nothing (its
-    // defaults are correct already).
-    std::string getSimpleCollationClause() const;
-
     // Call `op` back with the specific database backend subtype in use.
     template <typename T>
     T doDatabaseTypeSpecificOperation(DatabaseTypeSpecificOperation<T>& op);
@@ -192,12 +178,6 @@ doDatabaseTypeSpecificOperation(soci::session& session,
     if (auto sq = dynamic_cast<soci::sqlite3_session_backend*>(b))
     {
         return op.doSqliteSpecificOperation(sq);
-#ifdef USE_POSTGRES
-    }
-    else if (auto pg = dynamic_cast<soci::postgresql_session_backend*>(b))
-    {
-        return op.doPostgresSpecificOperation(pg);
-#endif
     }
     else
     {

src/database/DatabaseTypeSpecificOperation.h

@@ -5,9 +5,6 @@
 // of this distribution or at http://www.apache.org/licenses/LICENSE-2.0
 
 #include <lib/soci/src/backends/sqlite3/soci-sqlite3.h>
-#ifdef USE_POSTGRES
-#include <lib/soci/src/backends/postgresql/soci-postgresql.h>
-#endif
 
 // Just a visitor type to help write code that's database-specific.
 // See Database::doDatabaseTypeSpecificOperation.
@@ -17,9 +14,5 @@ template <typename T = void> class DatabaseTypeSpecificOperation
 {
   public:
     virtual T doSqliteSpecificOperation(soci::sqlite3_session_backend* sq) = 0;
-#ifdef USE_POSTGRES
-    virtual T
-    doPostgresSpecificOperation(soci::postgresql_session_backend* pg) = 0;
-#endif
 };
 }