The code for checking that an MV's select statement doesn't
have any bind markers uses the wrong method and always returns
`false` even when it should not.
`prepare_context::empty()` is a misleading name because
it doesn't check if the current instance is empty, but creates
an empty instance wrapped in a `lw_shared_ptr` instead.
Thus, the code in `create_view_statement::announce_migration()`
checks that the pointer is not empty, which is always false.
Use `get_variable_specifications().empty()` to check that the
specifications vector inside the `prepare_context`
instance is not empty.
Tests: unit(dev)
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
"
`function_call` AST nodes are created for each function
with side effects in a CQL query, i.e. non-deterministic
functions (`uuid()`, `now()` and some others timeuuid-related).
These nodes are evaluated either when a query itself is executed
or query restrictions are computed (e.g. partition/clustering
key ranges for LWT requests).
We need to cache the calls since otherwise when handling a
`bounce_to_shard` request for an LWT query, we can possibly
enter an infinite bouncing loop (in case a function is used
to calculate partition key ranges for a query), since the
results can be different each time.
Furthermore, we don't support bouncing more than one time.
Returning `bounce_to_shard` message more than one time
will result in a crash.
Caching works only for LWT statements and only for the function
calls that affect partition key range computation for the query.
`variable_specifications` class is renamed to `prepare_context`
and generalized to record information about each `function_call`
AST node and modify them, as needed:
* Check whether a given function call is a part of partition key
statement restriction.
* Assign ids for caching if above is true and the call is a part
of an LWT statement.
There is no need to include any kind of statement identifier
in the cache key since `query_options` (which holds the cache)
is limited to a single statement, anyway.
Function calls are indexed by the order in which they appear
within a statement while parsing. There is no need to
include any kind of statement identifier to the cache key
since `query_options` (which holds the cache) is limited
to a single statement, anyway.
Note that `function_call::raw` AST nodes are not created
for selection clauses of a SELECT statement hence they
can only accept only one of the following things as parameters:
* Other function calls.
* Literal values.
* Parameter markers.
In other words, only parameters that can be immediately reduced
to a byte buffer are allowed and we don't need to handle
database inputs to non-pure functions separately since they
are not possible in this context. Anyhow, we don't even have
a single non-pure function that accepts arguments, so precautions
are not needed at the moment.
Add a test written in `cql-pytest` framework to verify
that both prepared and unprepared lwt statements handle
`bounce_to_shard` messages correctly in such scenario.
Fixes: #8604
Tests: unit(dev, debug)
NOTE: the patchset uses `query_options` as a container for
cached values. This doesn't look clean and `service::query_state`
seems to be a better place to store them. But it's not
forwarded to most of the CQL code and would mean that a huge number
of places would have to be amended.
The series presents a trade-off to avoid forwarding `query_state`
everywhere (but maybe it's the thing that needs to be done, nonetheless).
"
* 'lwt_bounce_to_shard_cached_fn_v6' of https://github.com/ManManson/scylla:
cql-pytest: add a test for non-pure CQL functions
cql3: cache function calls evaluation for non-deterministic functions
cql3: rename `variable_specifications` to `prepare_context`
Now that all selectable::raw subclasses have been converted to
cql3::selectable::with_expression::raw, the class structure is
just a wrapper around expressions. Peel it, converting the
virtual member functions to free functions, and replacing
object instances with expression or nested_expression as the
case allows.
Add a field_selection variant element to expression. Like function_call
and cast, the structure from which a field is selectewd cannot yet be
an expression, since not all seletable::raw:s are converted. This will
be done in a later pass. This is also why printing a field selection now
does not print the selected expression; this will also be corrected later.
Add a function_call variant element to hold function calls. Note
that because not all selectables are yet converted, function call
arguments are still of type selectable::raw. They will be converted
to expressions later. This is also why printing a function now
does not print its arguments; this will also be corrected later.
Create a new element in the expression variant, column_mutation_attribute,
signifying we're picking up an attribute of a column mutation (not a
column value!). We use an enum rather than a bool to choose between
writetime and ttl (the two mutation attributes) for increased
explicitness.
Although there can only be one type for the column we're operating
on (it must be an unresolved_identifer), we use a nested_expression.
This is because we'll later need to also support a column_value
as the column type after we prepare it. This is somewhat similar
to the address of operator in C, which syntactically takes any
expression but semantically operates only on lvalues.
Introduce unresolved_identifer as an unprepared counterpart to column_value.
column_identifier_raw no longer inherits from selectable::raw, but
methods for now to reduce churn.
Prepare to migrate selectable::raw sub-classes to expressions by
creating a bridge betweet the two types. with_expression::raw
is a selectable::raw and implements all its methods (right now,
trivially), and its contents is an expression. The methods are
implemented using the usual visitor pattern.
The class is repurposed to be more generic and also be able
to hold additional metadata related to function calls within
a CQL statement. Rename all methods appropriately.
Visitor functions in AST nodes (`collect_marker_specification`)
are also renamed to a more generic `fill_prepare_context`.
The name `prepare_context` designates that this metadata
structure is a byproduct of `stmt::raw::prepare()` call and
is needed only for "prepare" step of query execution.
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
After previous patches some places in cql3 code take a
long path to get database reference:
query processor -> storage proxy -> database
The query processor can provide the database reference
by itself, so take this chance.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
There are few schema altering statements that need to have
the query processor inside lambda continuations. Fortunately,
they all are continuations of make_ready_future<>()s, so the
query processor can be simply captured by reference and used.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Now when the only call to .announce_migration gas the
query processor at hands -- pass it to the real statements.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Currently there are places that call
keyspace_element_name::get_keyspace() without checking that _ks_name is
engaged. Fix those places.
Message-Id: <20210216085545.54753-1-gleb@scylladb.com>
It looks like the history of the flag begins in Cassandra's
https://issues.apache.org/jira/browse/CASSANDRA-7327 where it is
introduced to speedup tests by not needing to start the gossiper.
The thing is we always start gossiper in our cql tests, so the flag only
introduce noise. And, of course, since we want to move schema to use raft
it goes against the nature of the raft to be able to apply modification only
locally, so we better get rid of the capability ASAP.
Tests: units(dev, debug)
Message-Id: <20201230111101.4037543-2-gleb@scylladb.com>
First of all, select statement is extended with an 'attrs' field,
which keeps the per-query attributes. Currently, only TIMEOUT
parameter is legal to use, since TIMESTAMP and TTL bear no meaning
for reads.
Secondly, if TIMEOUT attribute is set, it will be used as the effective
timeout for a particular query.
It is called from cql3/statements' check_access methods and from thrift
handlers. The former have proxy argument from which they can get the
database. The latter already have the database itself on board.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
C++20 introduced `contains` member functions for maps and sets for
checking whether an element is present in the collection. Previously
the code pattern looked like:
<collection>.find(<element>) != <collection>.end()
In C++20 the same can be expressed with:
<collection>.contains(<element>)
This is not only more concise but also expresses the intend of the code
more clearly.
This commit replaces all the occurences of the old pattern with the new
approach.
Tests: unit(dev)
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Message-Id: <f001bbc356224f0c38f06ee2a90fb60a6e8e1980.1597132302.git.piotr@scylladb.com>
Before this patch, when db/view/view.hh was modified, 89 source files had to
be recompiled. After this patch, this number is down to 5.
Most of the irrelevant source files got view.hh by including database.hh,
which included view.hh just for the definition of statistics. So in this
patch we split the view statistics to a separate header file, view_stats.hh,
and database.hh only includes that. A few source files which included
only database.hh and also needed view.hh (for materialized-view related
functions) now need to include view.hh explicitly.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20200319121031.540-1-nyh@scylladb.com>
If sstring is made an alias to std::string ADL causes std::make_shared
to be found. Explicitly ask for ::make_shared.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Moves initialization of schema extensions outside of cf_prop_defs. This
allows to construct these extensions once, and use them several times in
cd_prop_defs' methods without caching or recalculating them several
times.
Changes cf_prop_defs::validate function to take database& as an argument
instead of db::extensions&. This change will allow us to move the check
which asserts that the cluster supports CDC from `apply_to_builder` to
`validate` method.
* Pass raw::select_statement::parameters as lw_shared_ptr
* Some more const cleanups here and there
* lists,maps,sets::equals now accept const-ref to *_type_impl
instead of shared_ptr
* Remove unused `get_column_for_condition` from modification_statement.hh
* More methods now accept const-refs instead of shared_ptr
Every call site where a shared_ptr was required as an argument
has been inspected to be sure that no dangling references are
possible.
Tests: unit(dev, debug)
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Message-Id: <20200220153204.279940-1-pa.solodovnikov@scylladb.com>
De-pointerize cql3 code APIs further: change some call sites
to pass `schema` as const-ref instead of `shared_ptr`.
Affected functions known to be expecting always non-null
pointer to schema and don't store or pass the pointer somewhere
else, assuming it's safe to give them just a reference.
Tests: unit(dev, debug)
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Message-Id: <20200218142338.69824-1-pa.solodovnikov@scylladb.com>
Convert some more helper functions to accept const reference to
column_specification and column_identifier instead of shared_ptr.
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
There's no local variable to get features from in the
create_view_statement constructor, but since the .validate
is always called after it, it looks safe to check for
needed feature in it (we have storage_proxy there).
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Keep local feature_service reference on database. This relaxes the
circular storage_service <-> database reference, but not removes it
completely.
This needs some args tossing in apply_to_builder, but it's
rather straightforward, so comes in the same patch.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
`parsed_statement::get_bound_variables` is assumed to always
return a nonnull pointer to `variable_specifications` instance.
In this case using a pointer is superfluous and can be safely
replaced by a plain reference.
Also add a default ctor and a utility method `set_bound_variables`
to the `variable_specifications` class to actually reset the
contents of the class instance.
Tests: unit(dev, debug)
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Message-Id: <20200120195839.164296-1-pa.solodovnikov@scylladb.com>
cql_statement is a class representing a prepared statement in Scylla.
It is used concurrently during execution, so it is important that its
change is not changed by execution.
Add const qualifier to the execution methods family, throghout the
cql hierarchy.
Mark a few places which do mutate prepared statement state during
execution as mutable. While these are not affecting production today,
as code ages, they may become a source of latent bugs and should be
moved out of the prepared state or evaluated at prepare eventually:
cf_property_defs::_compaction_strategy_class
list_permissions_statement::_resource
permission_altering_statement::_resource
property_definitions::_properties
select_statement::_opts
Extend the grammar file with GROUP BY, collect the column identifiers,
and store them in raw::select_statement.
Signed-off-by: Dejan Mircevski <dejan@scylladb.com>
When a materialized view was created, the verification code artificially
forbade creating a view without a clustering key column. However, there
is no real reason to forbid this. In the trivial case, the original base
table might not have had a clustering key, and the view might want to use
the exact same key. In a more complex case, a view may want to have all the
primary key columns as *partition* key columns, and that should be fine.
The patch also includes a regression test, which failed before this patch,
and succeeds with it (we test that we can create materialized views in both
aforementioned scenarios, and these materialized views work as expected).
Duarte raised the opinion that the "trivial" case of a view table with
a key identical to that of the base should be disallowed. However, this
should be done, if at all (I think it shouldn't), in a follow-up patch,
which will implement the non-triviality requirement consistently (e.g.,
require view primary key to be different from base's, regardless of
the existance or non-existance of clustering columns).
Fixes#4340.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20190320122925.10108-1-nyh@scylladb.com>
Three error messages were supposed to include a column name, but a "{}"
was missing in the format so the given column name didn't actually appear
in the error message. So this patch adds the missing {}'s.
Fixes#4183.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20190203112100.13031-1-nyh@scylladb.com>
This header, which is easily replaced with a forward declaration,
introduces a dependency on database.hh everywhere. Remove it and scatter
includes of database.hh in source files that really need it.
After this patch, the Materialized Views and Secondary Index features
are considered generally-available and no longer require passing an
explicit "--experimental=on" flag to Scylla.
The "--experimental=on" flag and the db::config::check_experimental()
function remain unused, as we graduated the only two features which used
this flag. However, we leave the support for experimental features in
the code, to make it easier to add new experimental features in the future.
Another reason to leave the command-line parameter behind is so existing
scripts that still use it will not break.
Fixes#3917
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20181115144456.25518-1-nyh@scylladb.com>
sprint() recently became more strict, throwing on sprint("%s", 5). Replace
with the more modern format().
Mechanically converted with https://github.com/avikivity/unsprint.
A materialized views can provide a filter so as to pick up only a subset
of the rows from the base table. Usually, the filter operates on columns
from the base table's primary key. If we use a filter on regular (non-key)
columns, things get hairy, and as issue #3430 showed, wrong: merely updating
this column in the base table may require us to delete, or resurrect, the
view row. But normally we need to do the above when the "new view key column"
was updated, when there is one. We use shadowable tombstones with one
timestamp to do this, so it cannot take into account the two timestamp from
those two columns (the filtered column and the new key column).
So in the current code, filtering by a non-key column does not work correctly.
In this patch we provide two test cases (one involving TTLs, and one involves
only normal updates), which demonstrate vividly that it does *not* work
correctly. With normal updates, trying to resurect a view row that has
previously disappeared, fails. With TTLs, things are even worse, and the view
row fails to disappear when the filtered column is TTLed.
In Cassandra, the same thing doesn't work correctly as well (see
CASSANDRA-13798 and CASSANDRA-13832) so they decided to refuse creating
a materialized view filtering a non-key column. In this patch we also
do this - fail the creation of such an unsupported view. For this reason,
the two tests mentioned above are commented out in a "#if", with, instead,
a trivial test verifying a failure to create such a view.
Note that as explained above, when the filtered column and new view key
column are *different* we have a problem. But when they are the *same* - namely
we filter by a non-key base column which actually *is* a key in the view -
we are actually fine. This patch includes additional test cases verifying
that this case is really fine and provides correct results. Accordingly,
this case is *not* forbidden in the view creation code.
Fixes#3430.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20181008185633.24616-1-nyh@scylladb.com>
When a view's partition key contains only columns from the base's partition
key (and not an additional one), the liveness (existance or disappearance)
of a view-table row is tied to the liveness of the base table row - and
that depends not only on selected columns (base-table columns SELECTed to
also appear in the view) but also on unselected columns.
This means that we may need to keep a view row alive even without data,
just because some unselected column is alive in the base table. Before this
patch we tried to build a single "row marker" in the view column which
summarizes the liveness information in all unselected columns, but this
proved unworkable, as explained in issue #3362 and as will be demonstrated
in unit tests in a later patch.
Because we can't replace several unselected cells by one row marker, what
we do in this patch is to add for each for the unselected cell a "virtual
cell" which contains the cell's liveness information (timestamp, deletion,
ttl) but not its value. For collections, we can't represent the entire
collection by one virtual cell, and rather need a collection of virtual
cells.
This patch just adds the virtual columns to the view schema. Code in
the previous patch, when it notices the virtual columns in the view's
schema, added the appropriate content into these columns.
We may need to add virtual columns to a view when first created, but also
when an unselected column is added to the base table with "ALTER TABLE",
so both are supported in this patch.
Fixes#3362.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
The storage_proxy represents the entire cluster, so there's never a need
to access it on a remote shard; the local shard instance will contact
remote shard or remote nodes as needed.
Simplify the API by passing storage_proxy references instead of
seastar::sharded<storage_proxy> references. query_processor and
other callers are adjusted to call seastar::sharded::local() first.
Message-Id: <20180415142656.25370-2-avi@scylladb.com>
Changed the order to check a couple of error conditions *after* checking
for too many or missing primary key columns. This order (showing the
too many or missing key columns first) is more useful, and is the order
in Cassadra's code.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20180320161121.13392-2-nyh@scylladb.com>
A view's primary key must include all the columns of the base's primary
key. If we don't check this and fail the table's creation, we can discover
problems later on when using the table, as demonstrated in issue #2720.
We had such checking code (translated from the same code in Java) but it
had an extra "else" which caused nothing to be put in "missing_pk_columns"
so the error was never recognized.
Also, when the error does happen, we should print the column's name_as_text(),
not name() which is (surprisingly) just a number.
Fixes#2720.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20180320161121.13392-1-nyh@scylladb.com>
