BLOB column type is represented by SCALAR field type in terms of NoSQL.
We attempted at emulating BLOB behaviour, but such efforts turn out to
be not decent enough. For this reason, we've decided to abandon these
attempts and fairly replace it with SCALAR column type.  SCALAR column
type acts in the same way as it does in NoSQL: it is aggregator-type for
INTEGER, NUMBER and STRING types. So, column declared with this type can
contain values of these three (available in SQL) types. It is worth
mentioning that CAST operator in this case does nothing.

Still, we consider BLOB values as entries encoded in msgpack with MP_BIN
format. To make this happen, values to be operated should be represented
in BLOB form x'...' (e.g. x'000000'). What is more, there are two
built-in functions returning BLOBs: randomblob() and zeroblob().  On the
other hand, columns with STRING NoSQL type don't accept BLOB values.

Closes #4019
Closes #4023

@TarantoolBot document
Title: SQL types changes
There are couple of recently introduced changes connected with SQL
types.

Firstly, we've removed support of DATE/TIME types from parser due to
confusing behaviour of these types: they were mapped to NUMBER NoSQL
type and have nothing in common with generally accepted DATE/TIME types
(like in other DBs). In addition, all built-in functions related to
these types (julianday(), date(), time(), datetime(), current_time(),
current_date() etc) are disabled until we reimplement TIME-like types as
a native NoSQL ones (see #3694 issue).

Secondly, we've removed CHAR type (i.e. alias to VARCHAR and TEXT). The
reason is that according to ANSI SQL CHAR(len) must accept only strings
featuring length exactly equal to given in type definition. Obviously,
now we don't provide such checks. Types VARCHAR and TEXT are still
legal.

For the same reason, we've removed NUMERIC and DECIMAL types, which were
aliases to NUMBER NoSQL type. REAL, FLOAT and DOUBLE are still exist as
aliases.

Finally, we've renamed BLOB column type to SCALAR. We've decided that
all our attempts to emulate BLOB behaviour using SCALAR NoSQL type don't
seem decent enough, i.e. without native NoSQL type BLOB there always
will be inconsistency, especially taking into account possible NoSQL-SQL
interactions. In SQL SCALAR type works exactly in the same way as in
NoSQL: it can store values of INTEGER, FLOAT and TEXT SQL types at the
same time. Also, with this change behaviour of CAST operator has been
slightly corrected: now cast to SCALAR doesn't affect type of value at
all. Couple of examples:

CREATE TABLE t1 (a SCALAR PRIMARY KEY);
INSERT INTO t1 VALUES ('1');
SELECT * FROM t1 WHERE a = 1;
-- []
Result is empty set since column "a" contains string literal value '1',
not integer value 1.

CAST(123 AS SCALAR); -- Returns 123 (integer)
CAST('abc' AS SCALAR); -- Returns 'abc' (string)

Note that in NoSQL values of BLOB type defined as ones decoded in
msgpack with MP_BIN format. In SQL there are still a few ways to force
this format: declaring literal in "BLOB" format (x'...') or using one of
two built-in functions (randomblob() and zeroblob()). TEXT and VARCHAR
SQL types don't accept BLOB values:

CREATE TABLE t (a TEXT PRIMARAY KEY);
INSERT INTO t VALUES (randomblob(5));
---
- error: 'Tuple field 1 type does not match one required: expected string'
...

BLOB itself is going to be reimplemented in scope of #3650.

NMERIC and DECIMAL were allowed to be specified as column types. But in
fact, they were just synonyms for FLOAT type and mapped to NUMERIC
Tarantool NoSQL type. So, we've decided to remove this type from parser
and return back when NUMERIC will be implemented as a native type.

Part of #4019

Currently, there is no native (in Tarantool terms) types to represent
time-like types. So, until we add implementation of those types, it
makes no sense to allow to specify those types in table definition.
Note that previously they were mapped to NUMBER type. For the same
reason all built-in functions connected with DATE/TIME are disabled as
well.

Part of #4019

Add optional 'chars' parameter to string.strip, string.lstrip
and string.rstrip for specifying the unwanted characters.
Behavior modeled after the equivalent Python built-ins.

Closes: #2977

@TarantoolBot document
Title: string.strip(inp, chars)
Update the documentation for string.strip,
string.lstrip and string.rstrip to reflect
the addition of the optional param.

Replace all usage of sqlite3_, sqlite, SQLite prefixes with simple sql_
All other occurrences of SQLite are substituted with SQL word.
SQL test suit is purified as well.

Nikita Pettik suggests me that free(NULL) is no-op according to POSIX.

This is follow up of 9dbcaa3a.

Make os.exit() call tarantool_exit(), just like the signal handler does.
Now on_shutdown triggers are not run only when a fatal signal is
received.

Closes #1607

@TarantoolBot document
Title: Document box.ctl.on_shutdown triggers
on_shutdown triggers may be set similar to space:on_replace triggers:
```
box.ctl.on_shutdown(new_trigger, old_trigger)
```
The triggers will be run when tarantool exits due to receiving one of
the signals: `SIGTERM`, `SIGINT`, `SIGHUP` or when user executes
`os.exit()`.

Note that the triggers will not be run if tarantool receives a fatal
signal: `SIGSEGV`, `SIGABORT` or any signal causing immediate program
termination.

The "box.sql.execute('values(blob)')" causes an accert in the
expression processing, because the parser doesn't distinguish the
keyword "BLOB" from the binary value (in the form X'hex').

This fix adds an additional checks in the SQL grammar.
Thus the expressions such as "VALUES(BLOB)", "SELECT FLOAT"
and so on are treated as a syntax errors.

Closes #3888

It catched by ASAN at build time (lemon is executed to generate
parse.[ch]), so tarantool couldn't be built with -DENABLE_ASAN=ON.

Allow exploring rocks documentation locally with
`tarantoolctl rocks doc ...`

In context of #3753

GLOB is a legacy extension for LIKE from SQLite. As we want our SQL to
be close to ANSI SQL & LIKE to depend on collations, we do not want to
support it. This patch totally removes it from Tarantool along with any
mentions of it.

Part of #3589
Part of #3572

As a main part of introducing strict typing in SQL it is required to
prohibit typeless columns in parser's grammar. Originally, SQLite simply
assigns typeless columns to BLOB affinity. Moreover, due to historical
reasons, all columns were stored with <SCALAR> type in Tarantool core
(except for <INTEGER> when it comes to primary key).  Column type should
be defined on table creation. Allowed data types are: <TEXT>, <VARCHAR>,
<CHAR>, <BLOB>, <INT[EGER]>, <REAL>, <FLOAT>, <NUMERIC>, <DECIMAL>,
<DOUBLE> <DATE> and <DATETIME>. However, still any declared data type is
converted to one of <BLOB>, <TEXT>, <REAL> or <INTEGER> affinities.
While affinity reaches space format, it is (again) converted to
Tarantool's field type. To be more precise, table of conversions:

+----------+----------+------------+
| SQL TYPE | AFFINITY | FIELD TYPE |
+----------+----------+------------+
| FLOAT    | REAL     | NUMBER     |
| REAL     | REAL     | NUMBER     |
| DOUBLE   | REAL     | NUMBER     |
| NUMERIC  | REAL     | NUMBER     |
| DECIMAL  | REAL     | NUMBER     |
| INTEGER  | INTEGER  | INTEGER    |
| TEXT     | TEXT     | STRING     |
| VARCHAR  | TEXT     | STRING     |
| CHAR     | TEXT     | STRING     |
| BLOB     | BLOB     | SCALAR     |
| DATETIME | REAL     | NUMBER     |
| DATE     | REAL     | NUMBER     |
| TIME     | REAL     | NUMBER     |
+----------+----------+------------+

<VARCHAR> and <CHAR> types should be specified with length
(e.g. name VARCHAR(10)), but this length currently is not used when
types are processed. Only purpose is to support ANSI syntax.
The same for <NUMERIC> and <DECIMAL> - it is allowed to specify scale
and precision, but they don't affect the way they are stored in memory.

Note that patch is not self-sufficient: a lot of tests still fail due to
wrong types conversions. Fix for that comes as next two patches.

Closes #3018
Closes #3104
Closes #2494
Closes #3459

If space.before_replace returns the old tuple, the operation turns into
no-op, but is still written to WAL as IPROTO_NOP for the sake of
replication. Such a request doesn't have a body, and tarantoolctl failed
to parse such requests in `tarantoolctl cat` and `tarantoolctl play`.
Fix this by checking whether a request has a body. Also skip such
requests in `play`, since they have no effect, and, while we're at it,
make sure `play` and `cat` do not read excess rows with lsn>=to in case
these rows are skipped.

Closes #3675

Closes #3311

As a part of SQL DD integration it is required to substitute SQLite
structure representing index with one from Tarantool internals.
To make this happen, lets add surrogate space to Table, which will
hold array of indexes. Those indexes are not real copies from Tarantool
core, but contain only index_def, since only def is useful during query
compilation.

Note that in new implementation indexes are held as array and added to
that array in straight order. In SQLite indexes are arranged in list and
added to the head. Hence, the order of indexes is reversed. It results
in different query plans: if planner must make choice of two equal
indexes, it chooses simply first one. Due to this change, some tests are
fixed.

Moreover, alongside with substituting index struct, <REINDEX> statement
and routine connected with it has been completely removed.

Part of #3561

A possibility to build tarantool with included library dependencies.
Use the flag -DBUILD_STATIC=ON to build statically against curl, readline,
ncurses, icu and z.
Use the flag -DOPENSSL_USE_STATIC_LIBS=ON to build with static
openssl

Changes:
  * Add FindOpenSSL.cmake because some distributions do not support the use of
  openssl static libraries.
  * Find libssl before curl because of build dependency.
  * Catch all bundled libraries API and export then it in case of static
  build.
  * Rename crc32 internal functions to avoid a name clash with linked libraries.

Notes:
  * Bundled libyaml is not properly exported, use the system one.
  * Dockerfile to build static with docker is included

Fixes #3445

We disabled ALTER TABLE ADD COLUMN long ago (i.e. banned in parser
ability to process this statement), but internal functions for handling
this routine have remained. This patch removes them as well.

Part of #3561

During startup tarantoolctl ignores 'pid_file' option and set it to
default value.
This cause a fault if user tries to execute config with option set.
In case of being started with tarantoolctl shadow this option with
additional wrapper around box.cfg.

Closes #3214

Fixing build under FreeBSD:
Undefined symbol "iconv_open"
Add compile time build check with FindICONV.cmake
and a wrapper to import relevant symbol names with include file.

Closes #3441

Tarantoolctl enter didn't check whether connection to a socket was
established if a socket file existed. It just executed a local console.
Fix this by adding a check and an error, also add a test case.

Closes #3364

If `tarantoolctl eval` fails, apart from returning 3 and printing the
eval error to stderr, tarantoolctl will also emit the following message:

  Error while reloading config:

This message is quite confusing and useless too, as we have the return
code for that. Let's zap it.

Closes #3560

According to #3072 log_nonblock cannot be used in
given case. This patch set this option to "false".

Closes #3348

`lua_tostring`/`lua_tolstring` ignores metatable/boolean/nil and return NULL,
but sometimes it's needed to have similar behaviour, like lua functions
tostring. Lua 5.1 and LuaJIT ignores it by default, Lua 5.2 introduced
auxilary function luaL_to(l)string with supporting of __tostring. This
function is backport of Lua 5.1 "lauxlib.h"s luaL_tostring in the luaT
namespace.

Resolves #3284.

We always compile with enabled foreign keys constraints. They still can
be turned off by <pragma foreign_keys = false> in runtime.

Follow-up #3271

After introducing separate space for persisting foreign key
constraints, nothing prevents us from adding ALTER TABLE statement to
add or drop named constraints. According to ANSI syntax is following:

ALTER TABLE <referencing table> ADD CONSTRAINT
  <referential constraint name> FOREIGN KEY
  <left paren> <referencing columns> <right paren> REFERENCES
  <referenced table> [ <referenced columns> ] [ MATCH <match type> ]
  [ <referential triggered action> ] [ <constraint check time> ]

ALTER TABLE <referencing table> DROP CONSTRAINT <constrain name>

In our terms it looks like:

ALTER TABLE t1 ADD CONSTRAINT f1 FOREIGN KEY(id, a)
    REFERENCES t2 (id, b) MATCH FULL;
ALTER TABLE t1 DROP CONSTRAINT f1;

FK constraints which come with CREATE TABLE statement are also
persisted with auto-generated name. They are coded after space and its
indexes.

Moreover, we don't use original SQLite foreign keys anymore: those
obsolete structs have been removed alongside FK hash. Now FK constraints
are stored only in space.

Since types of referencing and referenced fields must match, and now in
SQL only PK is allowed to feature INT (other fields are always SCALAR),
some tests have been corrected to obey this rule.

Part of #3271

This patch allow to use option "--language" with
"tarantoolctl enter" command. Also default value
for language were added in default configuration
file. Language is either SQL or Lua.

Closes #2385.

@TarantoolBot document
Title: Language selection for tarantoolctl
"enter".
User can select either Lua or SQL when he uses tarantoolctl
 "enter" command. It can be done using "--language=<language>"
syntax. Default language is set in tarantoolctl config file.
Usage:
tarantoolctl enter <app_name> --language=SQL
tarantoolctl enter <app_name> --language=Lua

The subcommands are used to create binary rock distributions.
In context of #3525

This pragma is dead and produces nothing else but segfault.
Along w/ this pragma, remove now dead opcodes which set/read
schema_version and all related routines.
Also, improve opcode generation script.

Part of #3541

To implement new TRUNCATE operation, we have introduced a
new P2 argument for OP_Clear opcode that calles box_truncate
instead of tarantoolSqlite3ClearTable.
This operation should work faster than DELETE FROM; but have
a few restricts.

Closes #2201.

@TarantoolBot document
Title: New TRUNCATE operation
TRUNCATE is DDL operation.
Removes all rows from a table or specified partitions of a table,
without logging the individual row deletions.
TRUNCATE TABLE is similar to the DELETE statement with no WHERE
clause; however, TRUNCATE TABLE is faster and uses fewer system
resources.
It couldn't be used with system tables or with tables having FKs.
It also couldn't be called in transaction.
The triggers on table will have ignored.
Example:
TRUNCATE TABLE t1;

Previously "BEGIN" / "BEGIN TRANSACTION", "COMMIT TRANSACTION" /
"END" / "END TRANSACTION", "ROLLBACK TRANSACTION" could be used
to handle transactions. By changing these commands syntax in
parser we're aiming on getting closer to ANSI SQL. Also found
initialization in ifdef that caused some problems with error
messages in occasions when the wrong syntax was used.

With the patch applied only following commands can be used:
 - "START TRANSACTION" to begin transaction.
 - "COMMIT" to end transaction.
 - "ROLLBACK" to rollback transaction without savepoints.
 - "ROLLBACK TO .." to rollback transaction to savepoint.

Closes #2164

Net.box usage for console is deprecated in 1.10,
replaced it with console.

Closes: #3490

Add propagation to luarocks of --only-server, --server keys.

Closes #2640

There are some hacks to know the instance was run by tarantoolctl,
none of them are too reliable, though. This patch introduces 2
environment variables set by tarantoolctl for the instance to
know when it's being run or restarted.

Closes: #3215

@TarantoolBot document
Title: tarantoolctl: document setting environment variables
tarantoolctl sets the `TARANTOOLCTL` environment variable when starting
an instance, and sets the `TARANTOOL_RESTARTED' environment variable
when restarting.

`sql_current_time` is exported only in debug mode and used to check
builtin datetime sql functions behavior in specific time moments.

Extra changes:
 * table-14.1 test is deleted, as it does not test anything.
   It was testing ddl inside of a transaction. This case is checked
   by 14.2 by now.

Closes #2646

In Tarantool VIEWs are always enabled, so there is no need for such
ifdef guards. This patch simply removes them.

According to ANSI Standard IS/IS NOT can be used to determine
if values is null. At the same time in SQLite3 IS/IS NOT have an
additional function - it can be used to check equality of two
values. This feature isn't common for different versions of SQL
(only in PL/SQL right operand can be NONE, TRUE of FALSE) This
patch removes described function.