1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
|
# Primitive data types
<!-- markdownlint-disable blanks-around-fences -->
The terms "simple", "primitive", and "elementary" data types are used synonymously.
## Numeric types {#numeric}
| Type | Description | Notes |
| ----- | ----- | ----- |
| `Bool` | Boolean value. |
| `Int8` | A signed integer.<br/>Acceptable values: from -2<sup>7</sup> to 2<sup>7</sup>–1. | |
| `Int16` | A signed integer.<br/>Acceptable values: from –2<sup>15</sup> to 2<sup>15</sup>–1. | |
| `Int32` | A signed integer.<br/>Acceptable values: from –2<sup>31</sup> to 2<sup>31</sup>–1. | |
| `Int64` | A signed integer.<br/>Acceptable values: from –2<sup>63</sup> to 2<sup>63</sup>–1. | |
| `Uint8` | An unsigned integer.<br/>Acceptable values: from 0 to 2<sup>8</sup>–1. | |
| `Uint16` | An unsigned integer.<br/>Acceptable values: from 0 to 2<sup>16</sup>–1. | |
| `Uint32` | An unsigned integer.<br/>Acceptable values: from 0 to 2<sup>32</sup>–1. | |
| `Uint64` | An unsigned integer.<br/>Acceptable values: from 0 to 2<sup>64</sup>–1. | |
| `Float` | A real number with variable precision, 4 bytes in size. | |
| `Double` | A real number with variable precision, 8 bytes in size. | |
| `Decimal` | A real number with the specified precision, up to 35 decimal digits | |
|`DyNumber` | A binary representation of a real number with an accuracy of up to 38 digits.<br/>Acceptable values: positive numbers from 1×10<sup>-130</sup> up to 1×10<sup>126</sup>–1, negative numbers from -1×10<sup>126</sup>–1 to -1×10<sup>-130</sup>, and 0.<br/>Compatible with the `Number` type in AWS DynamoDB. | |
## String types {#string}
| Type | Description | Notes |
| ----- | ----- | ----- |
| `String` | A string that can contain any binary data |
| `Utf8` | Text encoded in [UTF-8](https://en.wikipedia.org/wiki/UTF-8) |
| `Json` | [JSON](https://en.wikipedia.org/wiki/JSON) represented as text | Doesn't support matching |
| `JsonDocument` | [JSON](https://en.wikipedia.org/wiki/JSON) in an indexed binary representation | Doesn't support matching |
| `Yson` | [YSON](../udf/list/yson.md) in a textual or binary representation. | Doesn't support matching |
| `Uuid` | Universally unique identifier [UUID](https://tools.ietf.org/html/rfc4122) |
Unlike the `JSON` data type that stores the original text representation passed by the user, `JsonDocument` uses an indexed binary representation. An important difference from the point of view of semantics is that `JsonDocument` doesn't preserve formatting, the order of keys in objects, or their duplicates.
Thanks to the indexed view, `JsonDocument` lets you bypass the document model using `JsonPath` without the need to parse the full content. This helps efficiently perform operations from the [JSON API](../builtins/json.md), reducing delays and cost of user queries. Execution of `JsonDocument` queries can be up to several times more efficient depending on the type of load.
Due to the added redundancy, `JsonDocument` is less effective in storage. The additional storage overhead depends on the specific content, but is 20-30% of the original volume on average. Saving data in `JsonDocument` format requires additional conversion from the textual representation, which makes writing it less efficient. However, for most read-intensive scenarios that involve processing data from JSON, this data type is preferred and recommended.
{% note warning %}
To store numbers (JSON Number) in `JsonDocument`, as well as for arithmetic operations on them in the [JSON API](../builtins/json.md), the [Double](https://en.wikipedia.org/wiki/Double-precision_floating-point_format) type is used. Precision might be lost when non-standard representations of numbers are used in the source JSON document.
{% endnote %}
## Date and time {#datetime}
### Basic types
Value range for all basic datetime types: From midnight<sup>1</sup> 01.01.1970 to midnight<sup>1</sup> 01.01.2106.
Value range for basic interval type: from -136 years to +136 years.
| Type | Description | Notes |
|----- | ----- | ----- |
| `Date` | Time moment, representing the UTC midnight<sup>1</sup>, precision to the day | Internal representation: unsigned 16-bit integer |
| `Datetime` | UTC time moment, precision to second | Internal representation: unsigned 32-bit integer |
| `Timestamp` | UTC time moment, precision to microsecond | Internal representation: unsigned 64-bit integer |
| `Interval` | Time interval, precision to microseconds | Internal representation: signed 64-bit integer |
| `TzDate` | UTC time moment, representing the local midnight<sup>1</sup>, precision to the day | Internal representation: unsigned 16-bit integer with time zone id |
| `TzDateTime` | UTC time moment with time zone label, precision to second | Internal representation: unsigned 32-bit integer with time zone id |
| `TzTimestamp` | UTC time moment with time zone label, precision to microsecond | Internal representation: unsigned 64-bit integer with time zone id |
<sup>1</sup> Midnight is the particular time moment with all _time_ components being zero.
### Extended types
Value range for all basic datetime types: From midnight<sup>1</sup> 01.01.144169 BC to midnight<sup>1</sup> 01.01.148107.
Value range for basic interval type: from -292277 years to +292277 years.
| Type | Description | Notes |
|----- | ----- | ----- |
| `Date32` | Time moment, representing the UTC midnight<sup>1</sup>, precision to the day | Internal representation: signed 32-bit integer |
| `Datetime64` | UTC time moment, precision to second | Internal representation: signed 64-bit integer |
| `Timestamp64` | UTC time moment, precision to microsecond | Internal representation: signed 64-bit integer |
| `Interval64` | Time interval, precision to microseconds | Internal representation: signed 64-bit integer |
| `TzDate32` | UTC time moment, representing the local midnight<sup>1</sup>, precision to the day | Internal representation: signed 32-bit integer with time zone id |
| `TzDateTime64` | UTC time moment with time zone label, precision to second | Internal representation: signed 64-bit integer with time zone id |
| `TzTimestamp64` | UTC time moment with time zone label, precision to microsecond | Internal representation: signed 64-bit integer with time zone id |
<sup>1</sup> Midnight is the particular time moment with all _time_ components being zero.
### Supporting types with a time zone label
Time zone label for the `TzDate`, `TzDatetime`, `TzTimestamp` types is an attribute that is used:
* When converting ([CAST](../syntax/expressions.md#cast), [DateTime::Parse](../udf/list/datetime.md#parse), [DateTime::Format](../udf/list/datetime.md#format)) to a string and from a string.
* In [DateTime::Split](../udf/list/datetime.md#split), a timezone component is added to `Resource<TM>`.
The point in time for these types is stored in UTC, and the timezone label doesn't participate in any other calculations in any way. For example:
```yql
SELECT -- these expressions are always true for any timezones: the timezone doesn't affect the point in time.
AddTimezone(CurrentUtcDate(), "Europe/Moscow") ==
AddTimezone(CurrentUtcDate(), "America/New_York"),
AddTimezone(CurrentUtcDatetime(), "Europe/Moscow") ==
AddTimezone(CurrentUtcDatetime(), "America/New_York");
```
## Casting between data types {#cast}
### Explicit casting {#explicit-cast}
Explicit casting using [CAST](../syntax/expressions.md#cast):
#### Casting to numeric types
| Type | Bool | Int8 | Int16 | Int32 | Int64 | Uint8 | Uint16 | Uint32 | Uint64 | Float | Double | Decimal |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| **Bool** | — | Yes<sup>1</sup> | Yes<sup>1</sup> | Yes<sup>1</sup> | Yes<sup>1</sup> | Yes<sup>1</sup> | Yes<sup>1</sup> | Yes<sup>1</sup> | Yes<sup>1</sup> | Yes<sup>1</sup> | Yes<sup>1</sup> | No |
| **Int8** | Yes<sup>2</sup> | — | Yes | Yes | Yes | Yes<sup>3</sup> | Yes<sup>3</sup> | Yes<sup>3</sup> | Yes<sup>3</sup> | Yes | Yes | Yes | |
| **Int16** | Yes<sup>2</sup> | Yes<sup>4</sup> | — | Yes | Yes | Yes<sup>3,4</sup> | Yes<sup>3</sup> | Yes<sup>3</sup> | Yes<sup>3</sup> | Yes | Yes | Yes |
| **Int32** | Yes<sup>2</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | — | Yes | Yes<sup>3,4</sup> | Yes<sup>3,4</sup> | Yes<sup>3</sup> | Yes<sup>3</sup> | Yes | Yes | Yes |
| **Int64** | Yes<sup>2</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | — | Yes<sup>3,4</sup> | Yes<sup>3,4</sup> | Yes<sup>3,4</sup> | Yes<sup>3</sup> | Yes | Yes | Yes |
| **Uint8** | Yes<sup>2</sup> | Yes<sup>4</sup> | Yes | Yes | Yes | — | Yes | Yes | Yes | Yes | Yes | Yes |
| **Uint16** | Yes<sup>2</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes | Yes | Yes<sup>4</sup> | — | Yes | Yes | Yes | Yes | Yes |
| **Uint32** | Yes<sup>2</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes | Yes<sup>4</sup> | Yes<sup>4</sup> | — | Yes | Yes | Yes | Yes |
| **Uint64** | Yes<sup>2</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | — | Yes | Yes | Yes |
| **Float** | Yes<sup>2</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>3,4</sup> | Yes<sup>3,4</sup> | Yes<sup>3,4</sup> | Yes<sup>3,4</sup> | — | Yes | No |
| **Double** | Yes<sup>2</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>3,4</sup> | Yes<sup>3,4</sup> | Yes<sup>3,4</sup> | Yes<sup>3,4</sup> | Yes | — | No |
| **Decimal** | No | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | — |
| **String** | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| **Utf8** | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| **Json** | No | No | No | No | No | No | No | No | No | No | No | No |
| **Yson** | Yes<sup>5</sup> | Yes<sup>5</sup> | Yes<sup>5</sup> | Yes<sup>5</sup> | Yes<sup>5</sup> | Yes<sup>5</sup> | Yes<sup>5</sup> | Yes<sup>5</sup> | Yes<sup>5</sup> | Yes<sup>5</sup> | Yes<sup>5</sup> | No |
| **Uuid** | No | No | No | No | No | No | No | No | No | No | No | No |
| **Date** | No | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes | Yes | Yes<sup>4</sup> | Yes | Yes | Yes | Yes | Yes | Yes | No |
| **Datetime** | No | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes | Yes | Yes | Yes | No |
| **Timestamp** | No | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes | Yes | Yes | No |
| **Interval** | No | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes | Yes<sup>3,4</sup> | Yes<sup>3,4</sup> | Yes<sup>3,4</sup> | Yes<sup>3</sup> | Yes | Yes | No |
| **Date32** | No | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes | Yes | Yes<sup>4</sup> | Yes | Yes | Yes | Yes | Yes | Yes | No |
| **Datetime64** | No | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes | Yes | Yes | Yes | No |
| **Timestamp64** | No | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes | Yes | Yes | No |
| **Interval64** | No | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes<sup>4</sup> | Yes | Yes<sup>3,4</sup> | Yes<sup>3,4</sup> | Yes<sup>3,4</sup> | Yes<sup>3</sup> | Yes | Yes | No |
<sup>1</sup> `True` is converted to `1` and `False` to `0`.
<sup>2</sup> Any value other than `0` is converted to `True`, `0` is converted to `False`.
<sup>3</sup> Possible only in the case of a non-negative value.
<sup>4</sup> Possible only for the values from the target type value range.
<sup>5</sup> Using the built-in function [Yson::ConvertTo](../udf/list/yson.md#ysonconvertto).
#### Converting to date and time data types
##### Basic types
| Type | Date | Datetime | Timestamp | Interval |
| --- | --- | --- | --- | --- |
| **Bool** | No | No | No | No |
| **Int8** | Yes | Yes | Yes | Yes |
| **Int16** | Yes | Yes | Yes | Yes |
| **Int32** | Yes | Yes | Yes | Yes |
| **Int64** | Yes | Yes | Yes | Yes |
| **Uint8** | Yes | Yes | Yes | Yes |
| **Uint16** | Yes | Yes | Yes | Yes |
| **Uint32** | Yes | Yes | Yes | Yes |
| **Uint64** | Yes | Yes | Yes | Yes |
| **Float** | No | No | No | No |
| **Double** | No | No | No | No |
| **Decimal** | No | No | No | No |
| **String** | Yes | Yes | Yes | Yes |
| **Utf8** | Yes | Yes | Yes | Yes |
| **Json** | No | No | No | No |
| **Yson** | No | No | No | No |
| **Uuid** | No | No | No | No |
| **Date** | — | Yes | Yes | No |
| **Datetime** | Yes | — | Yes | No |
| **Timestamp** | Yes | Yes | — | No |
| **Interval** | No | No | No | — |
| **Date32** | Yes | Yes | Yes | No |
| **Datetime64** | Yes | Yes | Yes | No |
| **Timestamp64** | Yes | Yes | Yes | No |
| **Interval64** | No | No | No | Yes |
##### Extended types
| Type | Date32 | Datetime64 | Timestamp64 | Interval64 |
| --- | --- | --- | --- | --- |
| **Bool** | No | No | No | No |
| **Int8** | Yes | Yes | Yes | Yes |
| **Int16** | Yes | Yes | Yes | Yes |
| **Int32** | Yes | Yes | Yes | Yes |
| **Int64** | Yes | Yes | Yes | Yes |
| **Uint8** | Yes | Yes | Yes | Yes |
| **Uint16** | Yes | Yes | Yes | Yes |
| **Uint32** | Yes | Yes | Yes | Yes |
| **Uint64** | Yes | Yes | Yes | Yes |
| **Float** | No | No | No | No |
| **Double** | No | No | No | No |
| **Decimal** | No | No | No | No |
| **String** | Yes | Yes | Yes | Yes |
| **Utf8** | Yes | Yes | Yes | Yes |
| **Json** | No | No | No | No |
| **Yson** | No | No | No | No |
| **Uuid** | No | No | No | No |
| **Date** | Yes | Yes | Yes | No |
| **Datetime** | Yes | Yes | Yes | No |
| **Timestamp** | Yes | Yes | Yes | No |
| **Interval** | No | No | No | Yes |
| **Date32** | — | Yes | Yes | No |
| **Datetime64** | Yes | — | Yes | No |
| **Timestamp64** | Yes | Yes | — | No |
| **Interval64** | No | No | No | — |
#### Conversion to other data types
| Type | String | Utf8 | Json | Yson | Uuid |
| --- | --- | --- | --- | --- | --- |
| **Bool** | Yes | No | No | No | No |
| **INT** | Yes | No | No | No | No |
| **Uint** | Yes | No | No | No | No |
| **Float** | Yes | No | No | No | No |
| **Double** | Yes | No | No | No | No |
| **Decimal** | Yes | No | No | No | No |
| **String** | — | Yes | Yes | Yes | Yes |
| **Utf8** | Yes | — | No | No | No |
| **Json** | Yes | Yes | — | No | No |
| **Yson** | Yes<sup>4</sup> | No | No | No | No |
| **Uuid** | Yes | Yes | No | No | — |
| **Date** | Yes | Yes | No | No | No |
| **Datetime** | Yes | Yes | No | No | No |
| **Timestamp** | Yes | Yes | No | No | No |
| **Interval** | Yes | Yes | No | No | No |
| **Date32** | Yes | Yes | No | No | No |
| **Datetime64** | Yes | Yes | No | No | No |
| **Timestamp64** | Yes | Yes | No | No | No |
| **Interval64** | Yes | Yes | No | No | No |
<sup>4</sup> Using the built-in function [Yson::ConvertTo](../udf/list/yson.md#ysonconvertto).
##### Examples
{% include [x](../_includes/cast_examples.md) %}
### Implicit casting {#implicit-cast}
Implicit type casting that occurs in basic operations ( +-\*/) between different data types. The table cells specify the operation result type, if the operation is possible:
#### Numeric types
| Type | Int | Uint | Float | Double |
| --- | --- | --- | --- | --- |
| **INT** | — | `INT` | `Float` | `Double` |
| **Uint** | `INT` | — | `Float` | `Double` |
| **Float** | `Float` | `Float` | — | `Double` |
| **Double** | `Double` | `Double` | `Double` | — |
#### Date and time types
##### Basic types
| Type | Date | Datetime | Timestamp | Interval | TzDate | TzDatetime | TzTimestamp |
| --- | --- | --- | --- | --- | --- | --- | --- |
| **Date** | — | `DateTime` | `Timestamp` | — | `TzDate` | `TzDatetime` | `TzTimestamp` |
| **Datetime** | — | — | `Timestamp` | — | — | `TzDatetime` | `TzTimestamp` |
| **Timestamp** | — | — | — | — | — | — | `TzTimestamp` |
| **Interval** | — | — | — | — | — | — | — |
| **TzDate** | — | — | — | — | — | `TzDatetime` | `TzTimestamp` |
| **TzDatetime** | — | — | — | — | — | — | `TzTimestamp` |
| **TzTimestamp** | — | — | — | — | — | — | — |
| **Date32** | — | — | — | — | — | — | — |
| **Datetime64** | — | — | — | — | — | — | — |
| **Timestamp64** | — | — | — | — | — | — | — |
| **Interval64** | — | — | — | — | — | — | — |
| **TzDate32** | — | — | — | — | — | — | — |
| **TzDatetime64** | — | — | — | — | — | — | — |
| **TzTimestamp64** | — | — | — | — | — | — | — |
##### Extended types
| Type | Date32 | Datetime64 | Timestamp64 | Interval64 | TzDate32 | TzDatetime64 | TzTimestamp64 |
| --- | --- | --- | --- | --- | --- | --- | --- |
| **Date** | `Date32` | `DateTime64` | `Timestamp64` | — | `TzDate32` | `TzDatetime64` | `TzTimestamp64` |
| **Datetime** | — | `Datetime64` | `Timestamp64` | — | — | `TzDatetime64` | `TzTimestamp64` |
| **Timestamp** | — | — | `Timestamp64` | — | — | — | `TzTimestamp64` |
| **Interval** | — | — | — | — | — | — | — |
| **TzDate** | — | — | — | — | `TzDate32` | `TzDatetime64` | `TzTimestamp64` |
| **TzDatetime** | — | — | — | — | — | `TzDatetime64` | `TzTimestamp64` |
| **TzTimestamp** | — | — | — | — | — | — | `TzTimestamp64` |
| **Date32** | — | `DateTime64` | `Timestamp64` | — | `TzDate32` | `TzDatetime64` | `TzTimestamp64` |
| **Datetime64** | — | — | `Timestamp64` | — | — | `TzDatetime64` | `TzTimestamp64` |
| **Timestamp64** | — | — | — | — | — | — | `TzTimestamp64` |
| **Interval64** | — | — | — | — | — | — | — |
| **TzDate32** | — | — | — | — | — | `TzDatetime64` | `TzTimestamp64` |
| **TzDatetime64** | — | — | — | — | — | — | `TzTimestamp64` |
| **TzTimestamp64** | — | — | — | — | — | — | — |
|
