module SQLite3::Pragmas

This module is intended for inclusion solely by the Database class. It defines convenience methods for the various pragmas supported by SQLite3.

For a detailed description of these pragmas, see the SQLite3 documentation at sqlite.org/pragma.html.

Constants

AUTO_VACUUM_MODES: The enumeration of valid auto vacuum modes.
ENCODINGS: The list of valid encodings.
JOURNAL_MODES: The list of valid journaling modes.
LOCKING_MODES: The list of valid locking modes.
SYNCHRONOUS_MODES: The enumeration of valid synchronous modes.
TEMP_STORE_MODES: The enumeration of valid temp store modes.
WAL_CHECKPOINTS: The list of valid WAL checkpoints.

Public Instance Methods

application_id() click to toggle source

# File lib/sqlite3/pragmas.rb, line 143
def application_id
  get_int_pragma "application_id"
end

application_id=(integer) click to toggle source

# File lib/sqlite3/pragmas.rb, line 147
def application_id=(integer)
  set_int_pragma "application_id", integer
end

auto_vacuum() click to toggle source

# File lib/sqlite3/pragmas.rb, line 151
def auto_vacuum
  get_enum_pragma "auto_vacuum"
end

auto_vacuum=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 155
def auto_vacuum=(mode)
  set_enum_pragma "auto_vacuum", mode, AUTO_VACUUM_MODES
end

automatic_index() click to toggle source

# File lib/sqlite3/pragmas.rb, line 159
def automatic_index
  get_boolean_pragma "automatic_index"
end

automatic_index=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 163
def automatic_index=(mode)
  set_boolean_pragma "automatic_index", mode
end

busy_timeout() click to toggle source

# File lib/sqlite3/pragmas.rb, line 167
def busy_timeout
  get_int_pragma "busy_timeout"
end

busy_timeout=(milliseconds) click to toggle source

# File lib/sqlite3/pragmas.rb, line 171
def busy_timeout=(milliseconds)
  set_int_pragma "busy_timeout", milliseconds
end

cache_size() click to toggle source

# File lib/sqlite3/pragmas.rb, line 175
def cache_size
  get_int_pragma "cache_size"
end

cache_size=(size) click to toggle source

# File lib/sqlite3/pragmas.rb, line 179
def cache_size=(size)
  set_int_pragma "cache_size", size
end

cache_spill() click to toggle source

# File lib/sqlite3/pragmas.rb, line 183
def cache_spill
  get_boolean_pragma "cache_spill"
end

cache_spill=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 187
def cache_spill=(mode)
  set_boolean_pragma "cache_spill", mode
end

case_sensitive_like=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 191
def case_sensitive_like=(mode)
  set_boolean_pragma "case_sensitive_like", mode
end

cell_size_check() click to toggle source

# File lib/sqlite3/pragmas.rb, line 195
def cell_size_check
  get_boolean_pragma "cell_size_check"
end

cell_size_check=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 199
def cell_size_check=(mode)
  set_boolean_pragma "cell_size_check", mode
end

checkpoint_fullfsync() click to toggle source

# File lib/sqlite3/pragmas.rb, line 203
def checkpoint_fullfsync
  get_boolean_pragma "checkpoint_fullfsync"
end

checkpoint_fullfsync=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 207
def checkpoint_fullfsync=(mode)
  set_boolean_pragma "checkpoint_fullfsync", mode
end

collation_list() { |row| ... } click to toggle source

# File lib/sqlite3/pragmas.rb, line 211
def collation_list(&block) # :yields: row
  get_query_pragma "collation_list", &block
end

compile_options() { |row| ... } click to toggle source

# File lib/sqlite3/pragmas.rb, line 215
def compile_options(&block) # :yields: row
  get_query_pragma "compile_options", &block
end

count_changes() click to toggle source

# File lib/sqlite3/pragmas.rb, line 219
def count_changes
  get_boolean_pragma "count_changes"
end

count_changes=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 223
def count_changes=(mode)
  set_boolean_pragma "count_changes", mode
end

data_version() click to toggle source

# File lib/sqlite3/pragmas.rb, line 227
def data_version
  get_int_pragma "data_version"
end

database_list() { |row| ... } click to toggle source

# File lib/sqlite3/pragmas.rb, line 231
def database_list(&block) # :yields: row
  get_query_pragma "database_list", &block
end

default_cache_size() click to toggle source

# File lib/sqlite3/pragmas.rb, line 235
def default_cache_size
  get_int_pragma "default_cache_size"
end

default_cache_size=(size) click to toggle source

# File lib/sqlite3/pragmas.rb, line 239
def default_cache_size=(size)
  set_int_pragma "default_cache_size", size
end

default_synchronous() click to toggle source

# File lib/sqlite3/pragmas.rb, line 243
def default_synchronous
  get_enum_pragma "default_synchronous"
end

default_synchronous=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 247
def default_synchronous=(mode)
  set_enum_pragma "default_synchronous", mode, SYNCHRONOUS_MODES
end

default_temp_store() click to toggle source

# File lib/sqlite3/pragmas.rb, line 251
def default_temp_store
  get_enum_pragma "default_temp_store"
end

default_temp_store=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 255
def default_temp_store=(mode)
  set_enum_pragma "default_temp_store", mode, TEMP_STORE_MODES
end

defer_foreign_keys() click to toggle source

# File lib/sqlite3/pragmas.rb, line 259
def defer_foreign_keys
  get_boolean_pragma "defer_foreign_keys"
end

defer_foreign_keys=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 263
def defer_foreign_keys=(mode)
  set_boolean_pragma "defer_foreign_keys", mode
end

encoding() click to toggle source

# File lib/sqlite3/pragmas.rb, line 267
def encoding
  get_enum_pragma "encoding"
end

encoding=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 271
def encoding=(mode)
  set_string_pragma "encoding", mode, ENCODINGS
end

foreign_key_check(*table) { |row| ... } click to toggle source

# File lib/sqlite3/pragmas.rb, line 275
def foreign_key_check(*table, &block) # :yields: row
  get_query_pragma "foreign_key_check", *table, &block
end

foreign_key_list(table) { |row| ... } click to toggle source

# File lib/sqlite3/pragmas.rb, line 279
def foreign_key_list(table, &block) # :yields: row
  get_query_pragma "foreign_key_list", table, &block
end

foreign_keys() click to toggle source

# File lib/sqlite3/pragmas.rb, line 283
def foreign_keys
  get_boolean_pragma "foreign_keys"
end

foreign_keys=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 287
def foreign_keys=(mode)
  set_boolean_pragma "foreign_keys", mode
end

freelist_count() click to toggle source

# File lib/sqlite3/pragmas.rb, line 291
def freelist_count
  get_int_pragma "freelist_count"
end

full_column_names() click to toggle source

# File lib/sqlite3/pragmas.rb, line 295
def full_column_names
  get_boolean_pragma "full_column_names"
end

full_column_names=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 299
def full_column_names=(mode)
  set_boolean_pragma "full_column_names", mode
end

fullfsync() click to toggle source

# File lib/sqlite3/pragmas.rb, line 303
def fullfsync
  get_boolean_pragma "fullfsync"
end

fullfsync=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 307
def fullfsync=(mode)
  set_boolean_pragma "fullfsync", mode
end

get_boolean_pragma(name) click to toggle source

Returns true or false depending on the value of the named pragma.

# File lib/sqlite3/pragmas.rb, line 13
def get_boolean_pragma(name)
  get_first_value("PRAGMA #{name}") != 0
end

get_enum_pragma(name) click to toggle source

Return the value of the given pragma.

# File lib/sqlite3/pragmas.rb, line 53
def get_enum_pragma(name)
  get_first_value("PRAGMA #{name}")
end

get_int_pragma(name) click to toggle source

Returns the value of the given pragma as an integer.

# File lib/sqlite3/pragmas.rb, line 80
def get_int_pragma(name)
  get_first_value("PRAGMA #{name}").to_i
end

get_query_pragma(name, *params) { |row| ... } click to toggle source

Requests the given pragma (and parameters), and if the block is given, each row of the result set will be yielded to it. Otherwise, the results are returned as an array.

# File lib/sqlite3/pragmas.rb, line 43
def get_query_pragma(name, *params, &block) # :yields: row
  if params.empty?
    execute("PRAGMA #{name}", &block)
  else
    args = "'" + params.join("','") + "'"
    execute("PRAGMA #{name}( #{args} )", &block)
  end
end

ignore_check_constraints=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 311
def ignore_check_constraints=(mode)
  set_boolean_pragma "ignore_check_constraints", mode
end

incremental_vacuum(pages) { |row| ... } click to toggle source

# File lib/sqlite3/pragmas.rb, line 315
def incremental_vacuum(pages, &block) # :yields: row
  get_query_pragma "incremental_vacuum", pages, &block
end

index_info(index) { |row| ... } click to toggle source

# File lib/sqlite3/pragmas.rb, line 319
def index_info(index, &block) # :yields: row
  get_query_pragma "index_info", index, &block
end

index_list(table) { |row| ... } click to toggle source

# File lib/sqlite3/pragmas.rb, line 323
def index_list(table, &block) # :yields: row
  get_query_pragma "index_list", table, &block
end

index_xinfo(index) { |row| ... } click to toggle source

# File lib/sqlite3/pragmas.rb, line 327
def index_xinfo(index, &block) # :yields: row
  get_query_pragma "index_xinfo", index, &block
end

integrity_check(*num_errors) { |row| ... } click to toggle source

# File lib/sqlite3/pragmas.rb, line 331
def integrity_check(*num_errors, &block) # :yields: row
  get_query_pragma "integrity_check", *num_errors, &block
end

journal_mode() click to toggle source

# File lib/sqlite3/pragmas.rb, line 335
def journal_mode
  get_enum_pragma "journal_mode"
end

journal_mode=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 339
def journal_mode=(mode)
  set_string_pragma "journal_mode", mode, JOURNAL_MODES
end

journal_size_limit() click to toggle source

# File lib/sqlite3/pragmas.rb, line 343
def journal_size_limit
  get_int_pragma "journal_size_limit"
end

journal_size_limit=(size) click to toggle source

# File lib/sqlite3/pragmas.rb, line 347
def journal_size_limit=(size)
  set_int_pragma "journal_size_limit", size
end

legacy_file_format() click to toggle source

# File lib/sqlite3/pragmas.rb, line 351
def legacy_file_format
  get_boolean_pragma "legacy_file_format"
end

legacy_file_format=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 355
def legacy_file_format=(mode)
  set_boolean_pragma "legacy_file_format", mode
end

locking_mode() click to toggle source

# File lib/sqlite3/pragmas.rb, line 359
def locking_mode
  get_enum_pragma "locking_mode"
end

locking_mode=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 363
def locking_mode=(mode)
  set_string_pragma "locking_mode", mode, LOCKING_MODES
end

max_page_count() click to toggle source

# File lib/sqlite3/pragmas.rb, line 367
def max_page_count
  get_int_pragma "max_page_count"
end

max_page_count=(size) click to toggle source

# File lib/sqlite3/pragmas.rb, line 371
def max_page_count=(size)
  set_int_pragma "max_page_count", size
end

mmap_size() click to toggle source

# File lib/sqlite3/pragmas.rb, line 375
def mmap_size
  get_int_pragma "mmap_size"
end

mmap_size=(size) click to toggle source

# File lib/sqlite3/pragmas.rb, line 379
def mmap_size=(size)
  set_int_pragma "mmap_size", size
end

optimize(bitmask = nil) click to toggle source

Attempt to optimize the database.

To customize the optimization options, pass bitmask with a combination of the Constants::Optimize masks.

See www.sqlite.org/pragma.html#pragma_optimize for more information.

# File lib/sqlite3/pragmas.rb, line 389
def optimize(bitmask = nil)
  if bitmask
    set_int_pragma "optimize", bitmask
  else
    execute("PRAGMA optimize")
  end
end

page_count() click to toggle source

# File lib/sqlite3/pragmas.rb, line 397
def page_count
  get_int_pragma "page_count"
end

page_size() click to toggle source

# File lib/sqlite3/pragmas.rb, line 401
def page_size
  get_int_pragma "page_size"
end

page_size=(size) click to toggle source

# File lib/sqlite3/pragmas.rb, line 405
def page_size=(size)
  set_int_pragma "page_size", size
end

parser_trace=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 409
def parser_trace=(mode)
  set_boolean_pragma "parser_trace", mode
end

query_only() click to toggle source

# File lib/sqlite3/pragmas.rb, line 413
def query_only
  get_boolean_pragma "query_only"
end

query_only=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 417
def query_only=(mode)
  set_boolean_pragma "query_only", mode
end

quick_check(*num_errors) { |row| ... } click to toggle source

# File lib/sqlite3/pragmas.rb, line 421
def quick_check(*num_errors, &block) # :yields: row
  get_query_pragma "quick_check", *num_errors, &block
end

read_uncommitted() click to toggle source

# File lib/sqlite3/pragmas.rb, line 425
def read_uncommitted
  get_boolean_pragma "read_uncommitted"
end

read_uncommitted=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 429
def read_uncommitted=(mode)
  set_boolean_pragma "read_uncommitted", mode
end

recursive_triggers() click to toggle source

# File lib/sqlite3/pragmas.rb, line 433
def recursive_triggers
  get_boolean_pragma "recursive_triggers"
end

recursive_triggers=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 437
def recursive_triggers=(mode)
  set_boolean_pragma "recursive_triggers", mode
end

reverse_unordered_selects() click to toggle source

# File lib/sqlite3/pragmas.rb, line 441
def reverse_unordered_selects
  get_boolean_pragma "reverse_unordered_selects"
end

reverse_unordered_selects=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 445
def reverse_unordered_selects=(mode)
  set_boolean_pragma "reverse_unordered_selects", mode
end

schema_cookie() click to toggle source

# File lib/sqlite3/pragmas.rb, line 449
def schema_cookie
  get_int_pragma "schema_cookie"
end

schema_cookie=(cookie) click to toggle source

# File lib/sqlite3/pragmas.rb, line 453
def schema_cookie=(cookie)
  set_int_pragma "schema_cookie", cookie
end

schema_version() click to toggle source

# File lib/sqlite3/pragmas.rb, line 457
def schema_version
  get_int_pragma "schema_version"
end

schema_version=(version) click to toggle source

# File lib/sqlite3/pragmas.rb, line 461
def schema_version=(version)
  set_int_pragma "schema_version", version
end

secure_delete() click to toggle source

# File lib/sqlite3/pragmas.rb, line 465
def secure_delete
  get_boolean_pragma "secure_delete"
end

secure_delete=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 469
def secure_delete=(mode)
  set_boolean_pragma "secure_delete", mode
end

set_boolean_pragma(name, mode) click to toggle source

Sets the given pragma to the given boolean value. The value itself may be true or false, or any other commonly used string or integer that represents truth.

# File lib/sqlite3/pragmas.rb, line 20
def set_boolean_pragma(name, mode)
  case mode
  when String
    case mode.downcase
    when "on", "yes", "true", "y", "t" then mode = "'ON'"
    when "off", "no", "false", "n", "f" then mode = "'OFF'"
    else
      raise SQLite3::Exception, "unrecognized pragma parameter #{mode.inspect}"
    end
  when true, 1
    mode = "ON"
  when false, 0, nil
    mode = "OFF"
  else
    raise SQLite3::Exception, "unrecognized pragma parameter #{mode.inspect}"
  end

  execute("PRAGMA #{name}=#{mode}")
end

set_enum_pragma(name, mode, enums) click to toggle source

Set the value of the given pragma to mode. The mode parameter must conform to one of the values in the given enum array. Each entry in the array is another array comprised of elements in the enumeration that have duplicate values. See synchronous, default_synchronous, temp_store, and default_temp_store for usage examples.

# File lib/sqlite3/pragmas.rb, line 62
def set_enum_pragma(name, mode, enums)
  match = if enums.is_a?(Array)
    # maybe deprecate this?
    enums.find { |p| p.find { |i| i.to_s.downcase == mode.to_s.downcase } }
  elsif mode.is_a?(String)
    enums.fetch(mode.downcase)
  else
    mode
  end

  unless match
    raise SQLite3::Exception, "unrecognized #{name} #{mode.inspect}"
  end

  execute("PRAGMA #{name}='#{match}'")
end

set_int_pragma(name, value) click to toggle source

Set the value of the given pragma to the integer value of the value parameter.

# File lib/sqlite3/pragmas.rb, line 86
def set_int_pragma(name, value)
  execute("PRAGMA #{name}=#{value.to_i}")
end

short_column_names() click to toggle source

# File lib/sqlite3/pragmas.rb, line 473
def short_column_names
  get_boolean_pragma "short_column_names"
end

short_column_names=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 477
def short_column_names=(mode)
  set_boolean_pragma "short_column_names", mode
end

shrink_memory() click to toggle source

# File lib/sqlite3/pragmas.rb, line 481
def shrink_memory
  execute("PRAGMA shrink_memory")
end

soft_heap_limit() click to toggle source

# File lib/sqlite3/pragmas.rb, line 485
def soft_heap_limit
  get_int_pragma "soft_heap_limit"
end

soft_heap_limit=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 489
def soft_heap_limit=(mode)
  set_int_pragma "soft_heap_limit", mode
end

stats() { |row| ... } click to toggle source

# File lib/sqlite3/pragmas.rb, line 493
def stats(&block) # :yields: row
  get_query_pragma "stats", &block
end

synchronous() click to toggle source

# File lib/sqlite3/pragmas.rb, line 497
def synchronous
  get_enum_pragma "synchronous"
end

synchronous=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 501
def synchronous=(mode)
  set_enum_pragma "synchronous", mode, SYNCHRONOUS_MODES
end

table_info(table) { |new_row| ... } click to toggle source

Returns information about table. Yields each row of table information if a block is provided.

# File lib/sqlite3/pragmas.rb, line 580
def table_info table
  stmt = prepare "PRAGMA table_info(#{table})"
  columns = stmt.columns

  needs_tweak_default =
    version_compare(SQLite3.libversion.to_s, "3.3.7") > 0

  result = [] unless block_given?
  stmt.each do |row|
    new_row = columns.zip(row).to_h

    tweak_default(new_row) if needs_tweak_default

    # Ensure the type value is downcased.  On Mac and Windows
    # platforms this value is now being returned as all upper
    # case.
    if new_row["type"]
      new_row["type"] = new_row["type"].downcase
    end

    if block_given?
      yield new_row
    else
      result << new_row
    end
  end
  stmt.close

  result
end

temp_store() click to toggle source

# File lib/sqlite3/pragmas.rb, line 505
def temp_store
  get_enum_pragma "temp_store"
end

temp_store=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 509
def temp_store=(mode)
  set_enum_pragma "temp_store", mode, TEMP_STORE_MODES
end

threads() click to toggle source

# File lib/sqlite3/pragmas.rb, line 513
def threads
  get_int_pragma "threads"
end

threads=(count) click to toggle source

# File lib/sqlite3/pragmas.rb, line 517
def threads=(count)
  set_int_pragma "threads", count
end

user_cookie() click to toggle source

# File lib/sqlite3/pragmas.rb, line 521
def user_cookie
  get_int_pragma "user_cookie"
end

user_cookie=(cookie) click to toggle source

# File lib/sqlite3/pragmas.rb, line 525
def user_cookie=(cookie)
  set_int_pragma "user_cookie", cookie
end

user_version() click to toggle source

# File lib/sqlite3/pragmas.rb, line 529
def user_version
  get_int_pragma "user_version"
end

user_version=(version) click to toggle source

# File lib/sqlite3/pragmas.rb, line 533
def user_version=(version)
  set_int_pragma "user_version", version
end

vdbe_addoptrace=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 537
def vdbe_addoptrace=(mode)
  set_boolean_pragma "vdbe_addoptrace", mode
end

vdbe_debug=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 541
def vdbe_debug=(mode)
  set_boolean_pragma "vdbe_debug", mode
end

vdbe_listing=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 545
def vdbe_listing=(mode)
  set_boolean_pragma "vdbe_listing", mode
end

vdbe_trace() click to toggle source

# File lib/sqlite3/pragmas.rb, line 549
def vdbe_trace
  get_boolean_pragma "vdbe_trace"
end

vdbe_trace=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 553
def vdbe_trace=(mode)
  set_boolean_pragma "vdbe_trace", mode
end

wal_autocheckpoint() click to toggle source

# File lib/sqlite3/pragmas.rb, line 557
def wal_autocheckpoint
  get_int_pragma "wal_autocheckpoint"
end

wal_autocheckpoint=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 561
def wal_autocheckpoint=(mode)
  set_int_pragma "wal_autocheckpoint", mode
end

wal_checkpoint() click to toggle source

# File lib/sqlite3/pragmas.rb, line 565
def wal_checkpoint
  get_enum_pragma "wal_checkpoint"
end

wal_checkpoint=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 569
def wal_checkpoint=(mode)
  set_string_pragma "wal_checkpoint", mode, WAL_CHECKPOINTS
end

writable_schema=(mode) click to toggle source

# File lib/sqlite3/pragmas.rb, line 573
def writable_schema=(mode)
  set_boolean_pragma "writable_schema", mode
end

Private Instance Methods

set_string_pragma(pragma_name, value, valid_values) click to toggle source

# File lib/sqlite3/pragmas.rb, line 613
def set_string_pragma(pragma_name, value, valid_values)
  valid_values.fetch(value.to_s.downcase) {
    raise SQLite3::Exception, "unrecognized #{pragma_name} #{value.inspect}"
  }
  set_enum_pragma(pragma_name, value, valid_values)
end

tweak_default(hash) click to toggle source

Since SQLite 3.3.8, the table_info pragma has returned the default value of the row as a quoted SQL value. This method essentially unquotes those values.

# File lib/sqlite3/pragmas.rb, line 637
def tweak_default(hash)
  case hash["dflt_value"]
  when /^null$/i
    hash["dflt_value"] = nil
  when /^'(.*)'$/m
    hash["dflt_value"] = $1.gsub("''", "'")
  when /^"(.*)"$/m
    hash["dflt_value"] = $1.gsub('""', '"')
  end
end

version_compare(v1, v2) click to toggle source

Compares two version strings

# File lib/sqlite3/pragmas.rb, line 621
def version_compare(v1, v2)
  v1 = v1.split(".").map { |i| i.to_i }
  v2 = v2.split(".").map { |i| i.to_i }
  parts = [v1.length, v2.length].max
  v1.push 0 while v1.length < parts
  v2.push 0 while v2.length < parts
  v1.zip(v2).each do |a, b|
    return -1 if a < b
    return 1 if a > b
  end
  0
end