1OSMIUM-INDEX-TYPES(5) OSMIUM-INDEX-TYPES(5)
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6 osmium-index-types - Index types used to store node locations
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9 The osmium add-locations-to-ways and osmium export commands have to
10 keep an index of the node locations in memory or in a temporary file on
11 disk while doing their work. There are several different ways this can
12 be done which have different advantages and disadvantages.
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14 Use the --show-index-types/-I option on these commands to show all
15 available index types. It depends on your operating system which index
16 types are available.
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18 Use the --index-type/-i option on these commands to set the index type
19 to be used.
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21 The default index type is flex_mem which will keep all data in memory
22 and works for small extracts as well as the whole planet file. It is
23 the right choice for almost all use cases if you have enough memory to
24 keep the whole index in memory.
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26 For the osmium export command, the special type none is used when read‐
27 ing from files with the node locations on the ways. (See osmium-add-
28 node-locations-to-ways(1) for how to get a file like this.)
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30 You can use one of the file-based indexes for the node location store
31 to minimize memory use, but performance will suffer. In this case use
32 sparse_file_array if you have a small or medium sized extract and
33 dense_file_array if you are working with a full planet or a really
34 large extract.
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36 When using the file-based index types (*_file_array), add the filename
37 you want to use for the index after a comma to the index types like so:
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39 ... -i dense_file_array,index.dat ...
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42 It depends on the index type used how much memory is needed:
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44 • For sparse_*_array types 16 bytes per node in the input file are
45 used.
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47 • For dense_*_array types 8 bytes times the largest node ID in the in‐
48 put file are used.
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50 The *_mem_* types use potentially up to twice this amount.
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52 The *mem* and *mmap* types store the data in memory, the *file* types
53 in a file on disk.
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55 The flex_mem type automatically switches between something similar to
56 sparse_mmap_array for smaller extracts and dense_mmap_array for larger
57 extracts or the whole planet file.
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59 If you specify the --verbose/-v option, Osmium will display how much
60 memory was used for the index.
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63 • osmium(1), osmium-add-locations-to-ways(1), osmium-export(1)
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65 • Osmium website (https://osmcode.org/osmium-tool/)
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67 • Index types (https://osmcode.org/osmium-concepts/#indexes)
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70 Copyright (C) 2013-2021 Jochen Topf <jochen@topf.org>.
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72 License GPLv3+: GNU GPL version 3 or later <https://gnu.org/li‐
73 censes/gpl.html>. This is free software: you are free to change and
74 redistribute it. There is NO WARRANTY, to the extent permitted by law.
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77 If you have any questions or want to report a bug, please go to
78 https://osmcode.org/contact.html
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81 Jochen Topf <jochen@topf.org>.
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85 1.13.1 OSMIUM-INDEX-TYPES(5)