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
292
293
294
295
296
297
298
299
300
301
302
303
---+ Search
Atlas exposes search over the metadata in two ways:
* Basic Search
* Advanced Search (DSL or Full-Text)
---++ Basic search
The basic search allows you to query using typename of an entity, associated classification/tag
and has support for filtering on the entity attribute(s) as well as the classification/tag attributes.
The entire query structure can be represented using the following JSON structure (called !SearchParameters)
<verbatim>
{
"typeName": "hive_table",
"excludeDeletedEntities": true,
"classification" : "",
"query": "",
"limit": 25,
"offset": 0,
"entityFilters": {
"attributeName": "name",
"operator": "contains",
"attributeValue": "testtable"
},
"tagFilters": null,
"attributes": [""]
}
</verbatim>
__Field description__
* typeName: The type of entity to look for
* excludeDeletedEntities: Should the search include deleted entities too (default: true)
* classification: Only include entities with given Classification/tag
* query: Any free text occurrence that the entity should have (generic/wildcard queries might be slow)
* limit: Max number of results to fetch
* offset: Starting offset of the result set (useful for pagination)
* entityFilters: Entity Attribute filter(s)
* tagFilters: Classification/tag Attribute filter(s)
* attributes: Attributes to include in the search result (default: include any attribute present in the filter)
Attribute based filtering can be done on multiple attributes with AND/OR condition.
*NOTE: The tagFilters and entityFilters field have same JSON structure.*
__Examples of filtering (for hive_table attributes)__
* Single attribute
<verbatim>
{
"typeName": "hive_table",
"excludeDeletedEntities": true,
"classification" : "",
"query": "",
"limit": 50,
"offset": 0,
"entityFilters": {
"attributeName": "name",
"operator": "contains",
"attributeValue": "testtable"
},
"tagFilters": null,
"attributes": [""]
}
</verbatim>
* Multi-attribute with OR
<verbatim>
{
"typeName": "hive_table",
"excludeDeletedEntities": true,
"classification" : "",
"query": "",
"limit": 50,
"offset": 0,
"entityFilters": {
"condition": "OR",
"criterion": [
{
"attributeName": "name",
"operator": "contains",
"attributeValue": "testtable"
},
{
"attributeName": "owner",
"operator": "eq",
"attributeValue": "admin"
}
]
},
"tagFilters": null,
"attributes": [""]
}
</verbatim>
* Multi-attribute with AND
<verbatim>
{
"typeName": "hive_table",
"excludeDeletedEntities": true,
"classification" : "",
"query": "",
"limit": 50,
"offset": 0,
"entityFilters": {
"condition": "AND",
"criterion": [
{
"attributeName": "name",
"operator": "contains",
"attributeValue": "testtable"
},
{
"attributeName": "owner",
"operator": "eq",
"attributeValue": "admin"
}
]
},
"tagFilters": null,
"attributes": [""]
}
</verbatim>
__Supported operators for filtering__
* LT (symbols: <, lt) works with Numeric, Date attributes
* GT (symbols: >, gt) works with Numeric, Date attributes
* LTE (symbols: <=, lte) works with Numeric, Date attributes
* GTE (symbols: >=, gte) works with Numeric, Date attributes
* EQ (symbols: eq, =) works with Numeric, Date, String attributes
* NEQ (symbols: neq, !=) works with Numeric, Date, String attributes
* LIKE (symbols: like, LIKE) works with String attributes
* STARTS_WITH (symbols: startsWith, STARTSWITH) works with String attributes
* ENDS_WITH (symbols: endsWith, ENDSWITH) works with String attributes
* CONTAINS (symbols: contains, CONTAINS) works with String attributes
__CURL Samples__
<verbatim>
curl -sivk -g
-u <user>:<password>
-X POST
-d '{
"typeName": "hive_table",
"excludeDeletedEntities": true,
"classification" : "",
"query": "",
"limit": 50,
"offset": 0,
"entityFilters": {
"condition": "AND",
"criterion": [
{
"attributeName": "name",
"operator": "contains",
"attributeValue": "testtable"
},
{
"attributeName": "owner",
"operator": "eq",
"attributeValue": "admin"
}
]
},
"tagFilters": null,
"attributes": [""]
}'
<protocol>://<atlas_host>:<atlas_port>/api/atlas/v2/search/basic
</verbatim>
---++ Advanced Search
---+++ Search DSL Grammar
The DSL exposes an SQL like query language for searching the metadata based on the type system.
The grammar for the DSL is below.
<verbatim>
queryWithPath: query ~ opt(WITHPATH)
query: querySrc ~ opt(loopExpression) ~ opt(groupByExpr) ~ opt(selectClause) ~ opt(orderby) ~ opt(limitOffset)
querySrc: rep1sep(singleQrySrc, opt(COMMA))
singleQrySrc = FROM ~ fromSrc ~ opt(WHERE) ~ opt(expr ^? notIdExpression) |
WHERE ~ (expr ^? notIdExpression) |
expr ^? notIdExpression |
fromSrc ~ opt(WHERE) ~ opt(expr ^? notIdExpression)
fromSrc: identifier ~ AS ~ alias | identifier
groupByExpr = GROUPBY ~ (LPAREN ~> rep1sep(selectExpression, COMMA) <~ RPAREN)
orderby: ORDERBY ~ expr ~ opt (sortOrder)
limitOffset: LIMIT ~ lmt ~ opt (offset)
offset: OFFSET ~ offsetValue
sortOrder = ASC | DESC
loopExpression: LOOP ~ (LPAREN ~> query <~ RPAREN) ~ opt(intConstant <~ TIMES) ~ opt(AS ~> alias)
selectClause: SELECT ~ rep1sep(selectExpression, COMMA)
countClause = COUNT ~ LPAREN ~ RPAREN
maxClause = MAX ~ (LPAREN ~> expr <~ RPAREN)
minClause = MIN ~ (LPAREN ~> expr <~ RPAREN)
sumClause = SUM ~ (LPAREN ~> expr <~ RPAREN)
selectExpression: expr ~ opt(AS ~> alias)
expr: compE ~ opt(rep(exprRight))
exprRight: (AND | OR) ~ compE
compE:
arithE ~ (LT | LTE | EQ | NEQ | GT | GTE) ~ arithE |
arithE ~ (ISA | IS) ~ ident |
arithE ~ HAS ~ ident |
arithE | countClause | maxClause | minClause | sumClause
arithE: multiE ~ opt(rep(arithERight))
arithERight: (PLUS | MINUS) ~ multiE
multiE: atomE ~ opt(rep(multiERight))
multiERight: (STAR | DIV) ~ atomE
atomE: literal | identifier | LPAREN ~> expr <~ RPAREN
identifier: rep1sep(ident, DOT)
alias: ident | stringLit
literal: booleanConstant |
intConstant |
longConstant |
floatConstant |
doubleConstant |
stringLit
</verbatim>
Grammar language:
{noformat}
opt(a) => a is optional
~ => a combinator. 'a ~ b' means a followed by b
rep => zero or more
rep1sep => one or more, separated by second arg.
{noformat}
Language Notes:
* A *!SingleQuery* expression can be used to search for entities of a _Trait_ or _Class_.
Entities can be filtered based on a 'Where Clause' and Entity Attributes can be retrieved based on a 'Select Clause'.
* An Entity Graph can be traversed/joined by combining one or more !SingleQueries.
* An attempt is made to make the expressions look SQL like by accepting keywords "SELECT",
"FROM", and "WHERE"; but these are optional and users can simply think in terms of Entity Graph Traversals.
* The transitive closure of an Entity relationship can be expressed via the _Loop_ expression. A
_Loop_ expression can be any traversal (recursively a query) that represents a _Path_ that ends in an Entity of the same _Type_ as the starting Entity.
* The _!WithPath_ clause can be used with transitive closure queries to retrieve the Path that
connects the two related Entities. (We also provide a higher level interface for Closure Queries
see scaladoc for 'org.apache.atlas.query.ClosureQuery')
* GROUPBY is optional. Group by can be specified with aggregate methods like max, min, sum and count. When group by is specified aggregated results are returned based on the method specified in select clause. Select expression is mandatory with group by expression.
* ORDERBY is optional. When order by clause is specified, case insensitive sorting is done based on the column specified.
For sorting in descending order specify 'DESC' after order by clause. If no order by is specified, then no default sorting is applied.
* LIMIT is optional. It limits the maximum number of objects to be fetched starting from specified optional offset. If no offset is specified count starts from beginning.
* There are couple of Predicate functions different from SQL:
* _is_ or _isa_can be used to filter Entities that have a particular Trait.
* _has_ can be used to filter Entities that have a value for a particular Attribute.
* Any identifiers or constants with special characters(space,$,",{,}) should be enclosed within backquote (`)
---++++ DSL Examples
For the model,
Asset - attributes name, owner, description
DB - supertype Asset - attributes clusterName, parameters, comment
Column - extends Asset - attributes type, comment
Table - supertype Asset - db, columns, parameters, comment
Traits - PII, Log Data
DSL queries:
* from DB
* DB where name="Reporting" select name, owner
* DB where name="Reporting" select name, owner orderby name
* DB where name="Reporting" select name limit 10
* DB where name="Reporting" select name, owner limit 10 offset 0
* DB where name="Reporting" select name, owner orderby name limit 10 offset 5
* DB where name="Reporting" select name, owner orderby name desc limit 10 offset 5
* DB has name
* DB is !JdbcAccess
* Column where Column isa PII
* Table where name="sales_fact", columns
* Table where name="sales_fact", columns as column select column.name, column.dataType, column.comment
* DB groupby(owner) select owner, count()
* DB groupby(owner) select owner, max(name)
* DB groupby(owner) select owner, min(name)
* from Person select count() as 'count', max(Person.age) as 'max', min(Person.age)
* `Log Data`
---+++ Full-text Search
Atlas also exposes a lucene style full-text search capability.