Databases
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    1. This table or related slice is empty.
    1. POstrstr faster than algorithms?
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    1. USAdam Rosenfield
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      1. VTUpMod
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    1. COThe effects of 4-byte-comparisons and SSE on string search are quite limited, unfortunately since there exist linear dependencies between the elements. In particular, you can’t just compare in non-overlapping 4-byte blocks: even if you compare 4 bytes at a time, you still need to compare overlapping blocks, not gaining much.
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      1. USKonrad Rudolph
    2. CO@Konrad: `strstr` can basically be implemented as a loop around `strchr` and `strcmp`/`memcmp` (with `memcmp` requiring an initial `strlen`). `strchr` can be implemented with some bit-twiddling tricks and doing 4-byte loads. `memcmp` can load 4 bytes at a time from each of the two comparands and compare those words. If the two operands don't have the same alignment, you keep track of two words at a time and bit-twiddle them to get the misaligned word to compare against the other string. See `sysdeps/x86_64/memcmp.S` in glibc, for example.
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      1. USAdam Rosenfield
    3. CO@Konrad: you gain something comparing the first 4 bytes of a pattern against a 4byte sliding window, shifting and inserting the next target string byte into the bottom of a 32bit word. It's not a much as you'd wish, since mixing 8 and 32 bit instructions on the same register stalls the instruction pipeline. SSE's a different story: you can compare 16 bytes from the target string with the first byte of the pattern, replicated 16 times. This seriously rocks. See my post below re an article with more details.
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      1. USMischa
 

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Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

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