diff --git a/src/box/sql/CMakeLists.txt b/src/box/sql/CMakeLists.txt
index b9dbe141a..f988dc3e7 100644
--- a/src/box/sql/CMakeLists.txt
+++ b/src/box/sql/CMakeLists.txt
@@ -10,9 +10,6 @@ set(SQL_BIN_DIR ${CMAKE_BINARY_DIR}/src/box/sql)
include_directories(${SQL_SRC_DIR})
include_directories(${SQL_BIN_DIR})

-add_definitions(-DSQL_MAX_WORKER_THREADS=0)
-add_definitions(-DSQL_OMIT_AUTOMATIC_INDEX)

-
set(TEST_DEFINITIONS
    SQL_NO_SYNC=1
    SQL_TEST=1

diff --git a/src/box/sql/sqlInt.h b/src/box/sql/sqlInt.h
index f019cd291..4bf94fad2 100644
--- a/src/box/sql/sqlInt.h
+++ b/src/box/sql/sqlInt.h

@@ -4858,13 +4846,6 @@ int sqlMemdebugNoType(void *, u8);

-/*
- * Threading interface
- */
-#if SQL_MAX_WORKER_THREADS>0
-int sqlThreadCreate(sqlThread **, void *(*)(void *), void *);
-int sqlThreadJoin(sqlThread *, void **);
-#endif

diff --git a/src/box/sql/vdbesort.c b/src/box/sql/vdbesort.c
index ddea6752c..a37fbd911 100644
--- a/src/box/sql/vdbesort.c
+++ b/src/box/sql/vdbesort.c
@@ -118,11 +118,6 @@
 * there are already N worker threads running, the main thread does the work
 * itself.
 *
- * The sorter is running in multi-threaded mode if (a) the library was built
- * with pre-processor symbol SQL_MAX_WORKER_THREADS set to a value greater
- * than zero, and (b) worker threads have been enabled at runtime by calling
- * "PRAGMA threads=N" with some value of N greater than 0.
- *
 * When Rewind() is called, any data remaining in memory is flushed to a
 * final PMA. So at this point the data is stored in some number of sorted
 * PMAs within temporary files on disk.
@@ -159,15 +154,6 @@
#include "sqlInt.h"
#include "vdbeInt.h"


/*
 * Hard-coded maximum amount of data to accumulate in memory before flushing
 * to a level 0 PMA. The purpose of this limit is to prevent various integer
@@ -297,18 +283,14 @@ struct MergeEngine {
 *
 * Before a background thread is launched, variable bDone is set to 0. Then,
 * right before it exits, the thread itself sets bDone to 1. This is used for
- * two purposes:

@@ -885,8 +848,8 @@ sqlVdbeSorterInit(sql * db, /* Database connection (for malloc()) */
} else {
pSorter->key_def = pCsr->key_def;
pSorter->pgsz = pgsz = 1024;
- pSorter->nTask = nWorker + 1;
- pSorter->iPrev = (u8) (nWorker - 1);
+ pSorter->nTask = 1;

diff --git a/src/box/sql/wherecode.c b/src/box/sql/wherecode.c
index 4dedb38a7..01fa138f6 100644
--- a/src/box/sql/wherecode.c
+++ b/src/box/sql/wherecode.c
@@ -253,14 +253,6 @@ sqlWhereExplainOneScan(Parse * pParse, /* Parse context */
      " USING INTEGER PRIMARY KEY (rowid%s?)",
      zRangeOp);
}
-#ifdef SQL_EXPLAIN_ESTIMATED_ROWS
- if (pLoop->nOut >= 10) {
- sqlXPrintf(&str, " (~%llu rows)",
-       sqlLogEstToInt(pLoop->nOut));
- } else {
- sqlStrAccumAppend(&str, " (~1 row)", 9);
- }
-#endif